Here is the list I have found so far. I am going to continue to post what I find.

1. Bluetooth Pairing is automatic doesn't ask for a passcode (unless you have a custom on set)
2. Customer Feedback to send usage data back to microsoft
3. Getting Started directions added instead of help
4. Remote Desktop Mobile included by default
5. Task Manager changes to show CPU usage and it appears to show all running processes not just programs
6. OneNOte Mobile added to the Office Mobile Programs
7. Automatic detection of Exchange Server Settings
8. Overall Performance seems to have improved a bit, a lot less waiting for programs to open (this may just be due to the reset of my device, but I have done the reset before and I could sware it took me longer in the past to reload everything)
9. Text message threading with Spell Checker
10. Managed programs added
11. Bluetooth issue when in call corrected
12. Domin enrollment
13. Vpn connections now work without wifi
14. Wifi search for networks will now list all networks within range
15. Defalt signicure of Sent from my Windows Mobile® phone.
16. You can switch to view processes in task manger