First look: Apple's new aesthetic for OS X Yosemite
OS X Yosemite -- the next version of Apple's venerable desktop operating system -- will bring a major visual overhaul to OS X for the first time in the software's history. AppleInsider takes a look at some of the changes coming this fall.

First impressions
Overall, OS X Yosemite sits in an uncanny valley between its more detailed heritage and the spartan adornment of iOS under Jony Ive. Some icons have an odd mix of flat and three-dimensional elements, for instance, and new form control animations -- such as the new slide/blink combination when switching radio buttons -- are slow and give an impression of lag in the operating system.
This is not particularly surprising, given the huge amount of baggage OS X carries and the monumental task of rebuilding the entire user experience of two flagship operating systems back to back, but the Apple human interface group has a long road ahead.
Finder

Finder maintains a familiar layout, but all of the icons and controls have been redesigned. Icons are slightly thinner and sharper, while controls are now a stark white-grey gradient. The side bar and toolbar are now translucent, allowing the background to show through.
Spotlight

Spotlight has been given the most radical makeover. No longer confined to its spot in the upper-right corner of the display, it will now show up as a translucent overlay in the middle of the screen. It also gains a built-in preview pane, making searching much easier.
Dock

The dock eschews the recent three-dimensionality and returns to its flat roots. The icons for default apps have been reimagined, but many of them retain elements of depth, unlike their more stark iOS counterparts.
Notification Center

Notification Center is now far more information-dense than it was in the past, and migrating widgets from the dashboard -- which still exists in the early Yosemite previews -- to Notification Center looks to be a welcome change. Notably, Notification Center is by far the most iOS-like design on the desktop, with virtually zero depth.
Safari

Much of Safari's functionality remains the same, but it comes in a far more compact layout. The favorites bar dropdown is jarring, and Apple would be wise to give users the option to disable it.
Notes & Reminders

Notes maintains its faux paper background, a glaring anomaly in the larger design concept, while Reminders now matches its iOS counterpart. Strangely, the Notes sidebar is not translucent -- the Reminders sidebar is -- and it remains to be seen whether this was a conscious choice or a mistake.

First impressions
Overall, OS X Yosemite sits in an uncanny valley between its more detailed heritage and the spartan adornment of iOS under Jony Ive. Some icons have an odd mix of flat and three-dimensional elements, for instance, and new form control animations -- such as the new slide/blink combination when switching radio buttons -- are slow and give an impression of lag in the operating system.
This is not particularly surprising, given the huge amount of baggage OS X carries and the monumental task of rebuilding the entire user experience of two flagship operating systems back to back, but the Apple human interface group has a long road ahead.
Finder

Finder maintains a familiar layout, but all of the icons and controls have been redesigned. Icons are slightly thinner and sharper, while controls are now a stark white-grey gradient. The side bar and toolbar are now translucent, allowing the background to show through.
Spotlight

Spotlight has been given the most radical makeover. No longer confined to its spot in the upper-right corner of the display, it will now show up as a translucent overlay in the middle of the screen. It also gains a built-in preview pane, making searching much easier.
Dock

The dock eschews the recent three-dimensionality and returns to its flat roots. The icons for default apps have been reimagined, but many of them retain elements of depth, unlike their more stark iOS counterparts.
Notification Center

Notification Center is now far more information-dense than it was in the past, and migrating widgets from the dashboard -- which still exists in the early Yosemite previews -- to Notification Center looks to be a welcome change. Notably, Notification Center is by far the most iOS-like design on the desktop, with virtually zero depth.
Safari

Much of Safari's functionality remains the same, but it comes in a far more compact layout. The favorites bar dropdown is jarring, and Apple would be wise to give users the option to disable it.
Notes & Reminders

Notes maintains its faux paper background, a glaring anomaly in the larger design concept, while Reminders now matches its iOS counterpart. Strangely, the Notes sidebar is not translucent -- the Reminders sidebar is -- and it remains to be seen whether this was a conscious choice or a mistake.
Comments
I do think they should have kept the same icons across the board for both iOS and OSX. Not sure why there is a difference.
Can't help but think of that moron in the other thread that said their round icons copied samsung tizen. Nothing changed to round.
As for the dock...I have the same thing on my PowerBook running Tiger.
I'm impartial about the UI color schemes. I like the lighter colors, lighter buttons, and starker contrast of color with it, but I find it kind of weird that the sidebars of apps are slightly transparent (like in Finder) and transparencies are laid seemingly randomly on top of each other... almost to "just do it". But as I have yet to use it in person because DP1's are normally terrible and I'm not willing to sacrifice my stable OS X for iOS 8 dev yet, I'm sure I'll have a stronger feeling (either positive or negative, I'm leaving room for either) towards it after a little playing around.
Overall, though, Yosemite will be ballin' in terms of the underlying components built into it.
I'm sure animation speeds and currently inconsistent UI features such as the non-translucent sidebar in Notes will be dealt with before the final release.
Overall I like it - especially the more compact title/toolbars on some apps - again I hope this extends to all the apps where this makes sense.
But the bookmarks feature in Safari really should move to a tool icon alongside the location bar.
I really did not like the new OS X. But will be migrating.
The color contrast is sharp against the too much WHITE quotient of the entire OS and its hurting eyes.
May be, I will run in poweruser mode.
Does Power user mode make windows look like HUD Windows? Or just the menus turn to Black?
SNOW LEOPARD: still the best.
I am still young (?) but still dont like the new colory colory peppy themes. 
Just look at the below screenshot, its just cool and gentle.
Of all, what I liked yesterday was the tight integration (correct word?) of Desktop OS with mobile OS. I am really happy that Apple is very keen on that and is making it. Great going. No other major company is doing it. (Microsoft has single OS for both mobile and Desktop OS, but still that is not right and relevant)
I wish Apple would finally end this Sturm und Drang aesthetic metamorphosis and get on with revamping major parts of the OS. What I keep hoping for is another Leopard- Snow Leopard release cycle, catching - and surpassing - competing operating systems in core technologies. Instead, Apple seems to be focussing on window dressing and extensions, and less on major components that need updating or overhaul, like the woeful file system, kludgy Finder, and awkward networking. Losing focus, Apple.
Can you still hide the Finder toolbar so the window behaviour reverts back to multi-window, spatial mode?
I'm astonished that people complain about little change. The pace has been remarkable. The technical moves are important however it serves the end-user experience. There are so many little changes that all add up to a fantastic whole. The search always seemed a little lost over there in the corner. Integration with iOS is huge: Continuity, Handoff, AirDrop, Cloud iDrive, SMS, phone integration. But iOS isn't the whole story. The platform is.
Not to beat on someone doing things badly, but I keep contrasting this progression of OSs with the zipping back and forth coming out of Redmond. They're thrashing around and generating lots and lots of talk but they've alienated the vast majority of their customers. They can't make an argument for upgrading. Anyone concerned that this is a ho hum roll out should consider what can go wrong with an OS upgrade.
OS X upgrades are done right. This is setting the stage for putting their ecosystem in service of our day to day needs.
I wish Apple would finally end this Sturm und Drang aesthetic metamorphosis and get on with revamping major parts of the OS. What I keep hoping for is another Leopard- Snow Leopard release cycle, catching - and surpassing - competing operating systems in core technologies. Instead, Apple seems to be focussing on window dressing and extensions, and less on major components that need updating or overhaul, like the woeful file system, kludgy Finder, and awkward networking. Losing focus, Apple.
I have to agree with you.
I wish Apple would finally end this Sturm und Drang aesthetic metamorphosis and get on with revamping major parts of the OS. What I keep hoping for is another Leopard- Snow Leopard release cycle, catching - and surpassing - competing operating systems in core technologies. Instead, Apple seems to be focussing on window dressing and extensions, and less on major components that need updating or overhaul, like the woeful file system, kludgy Finder, and awkward networking. Losing focus, Apple.
I'm sorry, but making such a statement as Apple losing focus, after yesterday's presentation and especially state of the union address makes me wonder whether we're living in the same reality.
Apple has shown that it is committed to developing the best software out there and enable third party devs to do so. They've invested heavily into new technologies. Just take a look at the new programming language, at the new dev tools, the APIs now available on iOS, etc. This is really HUGE.
For me personally, Apple just eliminated all doubts I might have had about the future. Don't worry, all those ageing matters will be resolved over time and it will once again be a surprise as huge as yesterday's announcements.
What we've seen now, is that Apple's investments into tools, compilers, etc, which happened over the past few years were not random. They've been working on those things with clear goals for the future. Yesterday it all came together and at the same time this is probably just the foundation of what is to come next.
I wish Apple would finally end this Sturm und Drang aesthetic metamorphosis and get on with revamping major parts of the OS...
What I see is a tick-tock every-other-year process with iOS and OS X. One year is powerful under-the-hood changes. The next is focused on lots of important surface elements that make people's experience better, easier and more rich. Last year's OS X had huge performance tweaks, and the iOS moved entirely to 64-bit. A huge undertaking. So this year is the tock year. Still seems like the Leopard/SnowLeopard process to me.
What I see is a tick-tock every-other-year process with iOS and OS X. One year is powerful under-the-hood changes. The next is focused on lots of important surface elements that make people's experience better, easier and more rich. Last year's OS X had huge performance tweaks, and the iOS moved entirely to 64-bit. A huge undertaking. So this year is the tock year. Still seems like the Leopard/SnowLeopard process to me.
As for OS X Yosemite, I see mostly interface gimmicks or extensions of existing capabilities. In five years, half will vanish or be renamed. "Tick-tock" is becoming a worn-out cliché in the industry. As the article points out, many features are still inconsistent in implementation. You would expect Apple to have finally settled the OS down in the tock cycle, if that is what Yosemite is supposed to be. iOS 64-bit - different article, mate. OS X Mavericks huge performance tweaks - not really. More hyperbole than substance, I fear.
I'm sorry, but making such a statement as Apple losing focus, after yesterday's presentation and especially state of the union address makes me wonder whether we're living in the same reality.
Apple has shown that it is committed to developing the best software out there and enable third party devs to do so. They've invested heavily into new technologies. Just take a look at the new programming language, at the new dev tools, the APIs now available on iOS, etc. This is really HUGE.
For me personally, Apple just eliminated all doubts I might have had about the future. Don't worry, all those ageing matters will be resolved over time and it will once again be a surprise as huge as yesterday's announcements.
What we've seen now, is that Apple's investments into tools, compilers, etc, which happened over the past few years were not random. They've been working on those things with clear goals for the future. Yesterday it all came together and at the same time this is probably just the foundation of what is to come next.
For a "cynic" you sure sound like the marketing department at Apple. I do want to ask you one question:
Just how many Computer Science Departments at US universities (or reputable international ones) will actually offer accredited classes in Swift as part of a CS or Engineering degree curriculum? Yeah, I seriously doubt it.
Dev tools, new APIs, this trick or that - in the end, if they sell more Macs and iPads, then great. Still, the core technologies of what an OS is supposed to do seem to have been neglected yet again.
What helped Apple reestablish itself and regain credibility and mindshare in the industry was its enthusiastic embrace of Unix and Intel. In recent years, they seem to be drifting back to the candy store mentality of the 90s with more proprietary technologies and a walled-garden approach.
Where is Apple's centre of gravity? No matter how big Apple may be presently, it still doesn't have the gravitational pull of the entire industry.
I hope I'm wrong, as I have a lifetime (and small fortune) invested in Apple tech ....
How is it a hot mess? And in what way did you expect it to be further along?
Congratulations, you're the only one that sees that. "Further along"? What? Well, I guess there always has to be someone like you with reactions that are completely mind boggling and disconnected from reality.
The big news here is Continuity, the suite of services that spread across Macs and iDevices. Not only are these interesting in their own right, but they represent capabilities that can't readily be implemented in competitive devices. (Windows 8/Phone could potentially be an exception to that; however they're not really a factor in the market.)
Focus schmocus! There's some real functionality built in to the new aesthetic, but in any case everybody adjusts to changes in appearance and moves on. Before long the previous normal comes to look, well, quaint.
The big news here is Continuity, the suite of services that spread across Macs and iDevices. Not only are these interesting in their own right, but they represent capabilities that can't readily be implemented in competitive devices. (Windows 8/Phone could potentially be an exception to that; however they're not really a factor in the market.)
Services? Yawn. They have been around for quite a while in OS X and still most people don't use them. Interoperability with iOS devices and OS X? Yeah, OK, I think they have been calling that convergence for a couple decades now. Still, I don't see that much to get excited over, yet.
Let's read what John Siracusa writes about Yosemite in a few months - then we'll have the final verdict.
To be clear, the improved Spotlight seems great and I look forward to using it, I just question the wisdom in moving the window.
Is it too soon to ask about Min-Sys-Reqts to run Yosemite?
I was pleasantly surprised when our early-2009 Al-Macbook (the 6-month window of Aluminum-but-not-Pro [no sD slot]), could run Mavericks. Core 2 Duo.
I'm imagining it will be (fairly) cut off from Yosemite.
How about a late 2009 27" iMac (the first 27", core i7). That should get Yosemite, yes?