Originally Posted by MJ1970
On what do you base this hypothesis? Gut feel? Wishful thinking?
Little bit of both, mostly the former. The world won't run on iPads and tablets can only get so large. I'd love a 15" iPad myself, but it would have to be thin and only as heavy as the 1st gen. And I'm a fringe in that regard; future tablets will probably bell curve around 12" (8" on the low end, 15" on the high). Even then, tablets won't be able to replace desktop power and capability for a decade or more, and that's pretending that traditional desktop/laptop chips ALSO won't be advancing in the interim.
I see the tablet leading the way in creating a new UI/X paradigm in the same way that the Apple ][ and Macintosh did. I see tablets completely replacing laptops in all but a scant few fringe cases (think… a percentage about like Linux in a non-server setting today). And even with tablets taking on this new role, there will still be stationary computers in the home. (After all, thinking that everyone will buy everything from iTunes and be able to store everything they'd want in iCloud is nonsense, so an Apple TV of the future will still have to have a computer of some sort off of which to pull local music, video, and picture content. ) Does that not make sense? People aren't going to have the entirety of their needs satisfied by just little tablets. An iPad can control your home* once it's automated, but it can't manage it—particularly when it's out and about with you at all times.
So as ever more people are born in a world that never knew anything before the iPad, the rest of computing will have to follow suit. I see the desktop of the future basically being a large iPad. Its screen will be able to transition between standing vertical and laying at a ~5º angle as seamlessly as the screen on the iMac G4 was adjusted. You'll interact with it down by your hands like the physical keyboard of today, but you'll also be able to consume content vertically (because having to look down to watch a trapezoidal movie is just plain stupid).
As such, the traditional "display" will exist for a good long while. I see dual displays taking on a slightly larger role than they do now; it would be connected to your desktop (even in just plain mirroring mode) to review the work that you're doing with your hands. It would save scant seconds of moving the computer up and down, but I can certainly see wanting to remain in the "groove". But purchasing a "display" would apply to both what we know as one today and to the retina dual-mode touchscreens that will be required for future desktops. After all, not all computers in the future will be iMacs, as well as that form factor works for 75% of people.
Look at the iMac today. Look at it over time since the G5 transition. What did the newest model bring? An edge thickness thin enough to be a smooth transition from the top of your desk to the screen of your computer. Crack off the foot (don't actually) and set it on your desk. I'd wager it's a pretty comfortable setup even now, when it's not yet designed to be!
Look at OS X. Why the heck do people THINK they're bringing iOS design (that's… UI design, as distinct from…) and interfacing into it? It's because an ever-growing number of people are not only using iOS devices as their first computer, but as their only computer. As the iPod "halo" brought people to early OS X (which, of course, couldn't operate the way an iPod could), the iPad "halo" will bring people to late OS X and OS XI, which will be designed with them in mind.
There will always be desktop computers. The definition thereof will simply be redefined. Just as they were when the Apple ][ was released and just as it was shortly after with the Macintosh. There was a time when 'a computer with a display' was nonsense. Now the opposite is unheard of. There was a time when the mouse was a 'toy'. And there will be a time when having a cursor show up on your screen will be considered as archaic as blinkenlights today.
*I want to talk about what I see for home automation, too, but this is an iPhone thread and I'm already ludicrously off-topic.