Some UI enhancements have come to the iPhone:
1. There's a satisfying click upon unlocking.
2. The transition to coverflow is now a fade in, not a twirl in (or whatever you'd call it), this would be both more seamless, and easier of the processor and battery.
3. The phone unlocking to main screen-transition is completely new. Before the home screen just appeared, now the locked slider screen fades to black, the date moves up out of screen, and the icons move in quickly from all sides.
4. Not a UI enhancement, but when the guy is looking for a restaurant he says "the closest would be?" GPS? Doubtful, but worth pointing out nonetheless.
5. The notes and calculator icons no longer have brown on them, which I did dislike for the calculator, but never minded for the notes app icon. On a side note I sent the feedback about hating the brown color on the calculator app icon on Jan 10th, just sayin'
6. The fade to call screen seems more seamless, which is great. Just a demo sure, but it's still cool.
7. The UI for the mid transition to an incoming call is new too. Before the screen just changed with no real transition, now it happens in a quick small series of smooth, planned, deliberate transitions.
All Apple's hard work on this iPhone will pay off for them, in the end.. big time.