Seas0nPass has been updated to support a TETHERED jailbreak of the new AppleTV 4.4 (iOS 5) software released on 10/12 (also supported are the new minor updates - 4.4.1 released on 10/17, 4.4.2 released on 10/24, 4.4.3 released on 11/17, and 4.4.4 released on 12/16). Full details on what's new in 4.4, status of 3rd party features, and how to update are below.
Should I update?
Currently the jailbreak for 4.4+ is tethered, which is a bit less convenient than an untethered version. If the features added in 4.4 excite you it may be worth updating; however, the previous 4.3 version will continue to be supported so updating is not required.