A video demonstration of this happening has now been uploaded to YouTube and shows a user logging in to the Apple TV and running commands as root.
SHAtter is a low level exploit that manages to break in to the Apple TV and other iOS 4.1 devices through a hardware issue.
As you can see, this Apple TV jailbreak isnâ€™t ready yet. But a public release will come soon
httpv://www.youtube.com/watch?v=adVp-IxcDHITags: Apple TV guides SHAtter