This flies in the face of the "It's new and different, so it's KEWL!" crowd, but the Leopard Dock throws away so many useful features of the current Dock...I don't know where to start...
\t-- The new white dot-thing under each active application makes it even more difficult to tell at a quick glance which apps are actually open (is that the "open application" dot? a reflection of part of the icon? an element of the Desktop picture showing through the translucent Dock?). For God's sake, has some Microsoft mole infiltrated the Leopard team? You have to pick the correct Desktop picture to get the dot-things to stand out so that you can tell with a quick glance what's open.
\t-- The new Stacks/Piles/Whatever needs an overhaul. For years I've been telling users (I'm the Mac Guy in a college IT department) to hold the mouse button down (or right-click) and you'll see the contents of any folder on the Dock. Now, if you hold the mouse button down (or right-click) you get the same "remove/open/show" menu you get if you perform that function on an application icon. To add injury to injury, single-clicking now brings up the Stacks/Piles/Whatever view, instead of opening the item. So now, the same action gives you two different results for Dock icons, whereas before there was only one -- click once on any item to open it. That Microsoft mole sure is doing a bang up job for Redmond.
And please, Apple, give us some nicer folder icons. It looks like Leopard was designed by Fisher Price.
-- Stacks on the Dock are sorted by default so that the last icon added is the icon that shows up on the Dock. If you add the Utilities folder to the Dock, for example, the icon that appears in the dock is NOT a folder, but whatever item is first in the list of the sort order(!) For real fun, right-click on the Utilities folder on the dock and change the "Sort by" setting.
Sort by Name and the Activity Monitor app icon now represents the Utilities *folder*
Sort by Date Added, and the Java folder icon shows up (at least it's a folder icon)
Sort by Date Modified, and it will change again (I added the latest version of Skim, so that icon now represents the Utilities *folder*
Sort by Date Created, and the VoiceOver Utility is now your Utilities folder icon
Sort by Kind, and we're back to Activity Monitor representing the Utilities folder
So kiss your Applications folder goodbye...dragging it to the Dock gives me the AddressBook icon. Bleah.
-- There is no way to adjust the font size for items in Dock Stacks/Piles/Whatever, so most of the names of items in the Applications folder are cut off. Also, if you want to put a folder onto the dock and actually make it LOOK like a folder, you have to sort the items in that folder so that an actual folder will be "first" and thus show its icon on the Dock. Otherwise, you might wind up with an application icon first in the icon sort, and thus show its icon in the area formerly reserved for actual folders.
It's a mess. Kiss your smooth workflow good-bye -- you'll spend half your time opening the wrong items from the "new and improved" Dock. I've gone back to keeping everything on the Desktop again. With hierarchical folders gone the only way I can access things quickly is with a 3rd party contextual plugin that lets me browse folders using a right-click.
And another thing...this stupid "Quick Look" uses the *spacebar* as it's hotkey (there's another command-key combo as well), so forget about using the spacebar to jump to the top of a folder list anymore. Buh bye! One more useful feature gone.
This is the first OS upgrade I've ever contemplated sitting out. It's that bad. Really.