I agree about UAC, it is definitely much improved in the release. It doesn't seem to totally drop you out of Aero like the UAC in Beta 2 does. Also, my HP PSC 2210 finally works, so Vista is a hell of a lot more useful than before. They also finally fixed a graphics issue where the OS became unusable when I tried to span the desktop between two different-sized monitors (I just got a black screen with just a mouse pointer). The RAM usage is also a hell of a lot better, but Media Center still runs like crap when it starts up. It is so bad, it makes you think the app is locked up at first.
Flip 3D looks a lot better with the antialiasing, but I still wish they would have gone for a shameless rip-off of Expose for the sake of the user experience. I'm guessing that we'll see more mice with a secondary application scroll wheel like the new logitech MX Revolution, which may make Flip 3D easier to deal with in the long run. I'm betting on a dedicated Flip 3D keyboard key in a lot of the new MS keyboards around year end as well.