FireCore has just released Seas0nPass 0.7.7 that features support for Lion and a handful of bug fixes. It’s generally designed to jailbreak your atv2 running iOS 4.3.x (Apple TV 2 4.2.2 software version) but, according to nitoTV, it also supports the latest iOS 5 beta.
Similar to PwnageTool, Seas0nPass allows you to jailbreak your atv2 by creating custom Apple TV IPSW files and restoring them in iTunes. It’s both Mac and Windows.
Read the entire article here:
How to Jailbreak Apple TV 2 on iOS 4.3 or iOS 5 Beta with Seas0nPass 0.7.7 (untethered).