Sprint and HTC finally for their act together and have released a WM 6.1 ROM upgrade for the Touch. They actually went a few steps further since Sprint chose to add in a few extra goodies. Sprint added support for EVDO Rev. A, threw in the Opera web browser, and added a new QWERTY keyboad. It seems that there may als obe some GSP navigation enhanvements in there as well.
Keep in mind that whenever you are upgrading your ROM, be sure to make a backup of all your data.
Sprint HTC Touch Windows Mobile 6.1 ROM download ( installation instructions)