1. Cut and Paste. Finally. Cut and paste of text on the iPhone works well, and is implemented in a way that could also work well on any touch-screen based computer.
2. Notes Sync. As many have said, it was silly/bizarre that this wasn’t supported on earlier versions of the iPhone OS. Notes is useful now!
3. Shake to Undo/Redo Typing. If you are typing something and wish to erase it and start over, all you have to do is deliberately shake your iPhone and it will be erased. If you want it back, simply shake again. I admit, the tactile experience of erasing a mistake by shaking it away is great. I wonder if Apple borrowed this idea from Etch-a-Sketch?
Honorable mention: swearing is now allowed on the new iPhone. Rod Blagojevich must be very happy.