The XBMC team have just announced XBMC for the latest version of Apple TV 5.2 (iOS 6.1). You will need to have jailbroken your Apple TV before you can the install on to the device. XBMC have a nice wiki with a guide on how to install XBMC on the Apple TV.
Head over to XBMC to get the update.
As many of you likely have been aware, neither XBMC nor any other non-Apple media center has been available for the updated Apple TV 2 Software 5.2 (iOS 6.1).
Now, we are pleased to announce that XBMC finally supports this update, thanks to the incredible work of XBMC dev Memphiz.
To get your updates on, head over to our wiki and follow the instructions for Apple TV version 5.0 and up.