HTC has released the Windows Mobile 6.1 Professional upgrade for the Sprint version of the HTC Touch.
The upgrade also adds EV-DO Rev. A functionality, the Opera web browser, enhanced GPS functionality including the Sprint Navigation application, and a full QWERTY virtual keyboard.
Note: The update will replace the current ROM image and will erase partnership and all user data and programs on your device. Be sure to back everything up before you start. HTC also indicates that the process can take up to 25 minutes.
Source: WMExperts