HTC has released the Windows Mobile 6.1 upgrade for the HTC TyTN II. It also comes with a display performance update that should help with video issues reported by some users.
It is available for download through the HTC e-Club. A free registration to the HTC e-Club is required.
No word yet on if and when AT&T Tilt users will get the upgrade.
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.