The FireCore Dev-Team recently tweeted that a new version of the Apple TV Jailbreaking solution, Seas0nPass is available to download. Unlike most updates for Seas0nPass that just bring on compatibility with new firmwares, Seas0nPass 0.8.2 comes with a new featured dubbed firmware stitching. What firmware stitching will allow you to do is downgrade your Apple TV to an earlier firmware version that Apple is no longer signing. You will of course have to have your signatures saved for a non-signed firmware however, in order to downgrade. This is similar to having to have saved SHSH blobs in order to downgrade your iPhone, iPod Touch or iPad to an earlier firmware version.
Firmware signatures are required to install a particular firmware version onto iOS devices like the AppleTV. When installing the latest version, these signatures will be created in real-time during the iTunes restore process. However, from time to time some firmware versions will stop being ‘signed’ by Apple, which will prevent them from being installed. Backing up your firmware signatures allows you to retain the ability to install an older firmware version in the future, should the need ever arise.