Personally, I think that dock thing is the ugliest thing ever. Trying to make it look like Mac with the dock instead of a taskbar is just odd. You can use shortcuts for program launchers and leave that space for a smaller, more useful taskbar with open window bars. I like eye candy (Compiz) but that only enhances the experience. Taking away the lower bar and replacing it with an enormous icon filled monstrosity...that will either make your windows shorter or it will get covered up, thus relying on alt-tab or win-tab to switch windows.
I'm glad they won't be using that dark brown prototype theme...that thing was ugly! I like the Human theme how it is in 8.04 (with the exception of the boring, outdated Firefox 3 theme, I made a new one that mimics the Strata theme for Windows but with orange icons to match Ubuntu).