Apple just recently released an update to the Apple TV Generation 2 (Version 4.1.1) and this update doesn't really bring along any new features but rather some usual bug fixes, and there not just your little security fixes but rather this fixes the ability for tv's to properly display 480p videos, as I had seen people on forums complain about the picture not display properly and also the update brings along a fix software wise, where sometimes content was being re-downloaded. Hopefully this will make the Apple TV much more stable. It is recommended that you do upgrade your Apple TV.

For more information, check out: Apple TV Update