A few days ago, apple released a software update for the apple tv, but this has caused major problems since then, so much so that apple have pulled the update from OTA.
The update is still available to do manually however. Currently you now have to plug it into your computer and restore it to update to version 6.0. But there are still problems even if you update it successfully.
If you successfully installed version 6.0 (build 11A470e) but don't like it and want to go back to 5.3 (build 10B809), here's how:
Depending on which type of atv you have download one of these:
atv2: http://appldnld.apple.com/AppleTV/091-5256.20130618.MagBg/AppleTV2,1_5.3_10B809_Restore.ipsw
atv3 (old): http://appldnld.apple.com/AppleTV/091-5257.20130618.Eu5uy/AppleTV3,1_5.3_10B809_Restore.ipsw
atv3 (new, i.e., 2013 model): http://appldnld.apple.com/AppleTV/091-5259.20130618.90Rft/AppleTV3,2_5.3_10B809_Restore.ipsw
Now plug it in to your computer with micro usb (and power on for atv3's, but not the atv2) and itunes on and do a restore BUT - hold down the option key when you click restore. That will let you select the ipsw file you just downloaded from which you can restore.
Note, if you don't hold down the option key and select the ipsw file, it will just reinstall version 6.0.
Note that apple may disable this downgrade possibility once they fix the version 6.0 problems and make it available OTA again (possibly with a higher build number).
The update is still available to do manually however. Currently you now have to plug it into your computer and restore it to update to version 6.0. But there are still problems even if you update it successfully.
If you successfully installed version 6.0 (build 11A470e) but don't like it and want to go back to 5.3 (build 10B809), here's how:
Depending on which type of atv you have download one of these:
atv2: http://appldnld.apple.com/AppleTV/091-5256.20130618.MagBg/AppleTV2,1_5.3_10B809_Restore.ipsw
atv3 (old): http://appldnld.apple.com/AppleTV/091-5257.20130618.Eu5uy/AppleTV3,1_5.3_10B809_Restore.ipsw
atv3 (new, i.e., 2013 model): http://appldnld.apple.com/AppleTV/091-5259.20130618.90Rft/AppleTV3,2_5.3_10B809_Restore.ipsw
Now plug it in to your computer with micro usb (and power on for atv3's, but not the atv2) and itunes on and do a restore BUT - hold down the option key when you click restore. That will let you select the ipsw file you just downloaded from which you can restore.
Note, if you don't hold down the option key and select the ipsw file, it will just reinstall version 6.0.
Note that apple may disable this downgrade possibility once they fix the version 6.0 problems and make it available OTA again (possibly with a higher build number).