According to an email I just got from Apple:
If you’ve installed the Apple TV 3.0 software update, you should immediately update to version 3.0.1. This prevents content from temporarily disappearing until it is resynced.
To do so:
1. Reboot your Apple TV (unplug the power cord and plug it back in)
2. Select Settings > General from the main menu
3. Select Update Software
4. Select Download and Install
