Microsoft recently release the 'March 2011' (aka NoDo) phone update. Unfortunately, not all phones are updated at the same time. An update schedule has been posted here: http://www.microsoft.com/windowsphone/en-us/features/update-schedule-world.aspx
If your phone is listed under 'Delivering update', you can 'trick' the Zune software & your phone to get the update anyways.
1. Start Zune on Your PC
2. Turn off Data connection ( Setting >System > Mobile Network > Data Connection ) and Wifi ( Setting >System > WiFi ) on the Phone
3. Connect the Phone with the PC (via USB)
4. Start the update search in Zune ( Settings > Phone > Update )
5. About 3 seconds later, disconnect your PC from the internet (Turn WLAN off)
6. Zune finds NoDo-Update. Press OK
7. Connect to the internet again on your PC and install the update
Worked like a charm for my phone (HTC Throphy)
The full story here & here
