A lot! My two big things are Threaded Text Messaging & Cut, Copy, and Paste on a Non-Touch Screen device :).
The only problem now is Version has not said it would update the Q 9m, looks like it's time to go shopping.
Windows Mobile 6.1 – New Windows Mobile Software for Pocket PC and Smartphone
Disclaimer The opinions expressed herein are my own personal opinions and do not represent my employer's view in anyway.