An updated version jailbreaking tool – Seas0nPass to support a tethered jailbreak the new Apple TV 4.2 software update (iOS 4.3) has been released by Firecore.
FireCore has also provided the following information about aTVFlash:
“For the most part yes. However, you may see a few oddities with text entry screens in plugins like Couch Surfer and nitoTV. These are relatively minor issues and should be a quick fix.”