AT&T Motorola Backflip Android 2.1 update from Nov 9
According to a leaked document, AT&T has already started pushing out the Android 2.1 update for Backflip to test users and will start it to everyone on November 9. Unless, something goes wrong in major way.
The update download will be available via Motorola website not over the air.
Update: Android 2.1 update is available now. Check here for more