Apple released a bug fix yesterday for their recently released Apple TV 4.4 update, which brought support for AirPlay mirroring for the iPad 2 & iPhone 4S, as well as Photo Stream, movie trailers, and content from the NHL and Wall Street Journal.
The update was issued to address minor bugs with the 4.4 update. Unfortunately, the update has bricked a number of Apple TV’s, requiring them to be forcibly restored through iTunes, and Apple has since pulled the update from their servers.
Even though the issue can be resolved by forcing a restore through iTunes to the previous version of the software, the best advice would be to steer clear of the 4.4.1 update, as its big fixes are relatively minor anyway, and wait for the next update from Apple.