Those of you who have an Apple TV and are wondering whether or not there will be any groundbreaking features in the iOS 6 firmware are unfortunately going to be disappointed. The only real significant feature that the iOS 6 firmware brings fourth in the Apple TV is rearrangeable icons.
Due to this fact it has been recommend by @NitoTV to not update to the iOS 6 firmware on your Apple TV if you are currently Jailbroken or would like to eventually Jailbreak the 1080p Apple TV 3.
If you do not rely on a Jailbreak for your Apple TV then of course by all means go ahead and update, but those who do Jailbreak DO NOT update until it is deemed safe. We should have confirmation of the safety of updating to iOS 6 for Jailbreakers soon, so keep your eyes on iJailbreak.