Couple of things i noticed:
-iTunes no longer moans at me about some of my items not being able to sync because i have an old version of iPhone software.
-When i dont have an edge signal, standard GPRS has a different logo
-Faster
-Problem with SMS messages where multiple instanses of conversation for one person would appear
-New 'Fetch New Data' in Settings has appeared, which alows you to change from diret push to fetch. You can also specify this on a per account level.
-Import SIM contacts has been moved to 'Mail, Contacts, Calender'
Thats all so far!