Apple has withdrawn the Apple TV v6.0 update
it issued on Friday. A number of early installers have reported
that the firmware bricked their set-top, rendering it unusable. Some people with less serious problems, such as a bad Wi-Fi connection, have nevertheless been forced to connect their hardware to iTunes via micro USB and restore to earlier firmware. Apple hasn't said when a fixed version of v6.0 might be available.
The firmware was intended to be a major update, opening access to iTunes Radio, streaming purchased music from iCloud, and AirPlaying iCloud content to someone else's Apple TV. It coincided with the launch of iTunes 11.1 and iOS 7 earlier in the week, which enabled iTunes Radio on Mac, Windows, and iOS devices.