Anyone who has modded their Apple IOS device recently may have run into a sticky situation where you had to plug your IOS device into a computer every single time you wanted to restart it. http://www.greenpois0n.com/ has just released version 6 of their jailbreak utility for ATV2, Iphones, Ipads, Itouches that allows for the untethered booting of Apple TV 2's running IOS version 4.2.1!!!
The best thing too is that it has been released for both Windows and MAC! I have Tried the Seas0nPass jailbreak, and greenpois0n is so much slicker, easier and quicker than it's counterparts!
On top of getting my ATV2 jailbroken, I have also installed XBMC and it works flawlessly! The only drawback that I have noticed is that the music visualizations do not appear be working correctly. I understand that the XBMC release is still relatively new (within the past two weeks) and that further updates should be forthcomming.
Check out XBMC at http://www.xbmc.org/
Now that I have xbmc on the Apple TV, I have a new one stop home center multimedia device for my living room television. I still love my Roku's...and hope that someday XBMC can be run off of them as well.
**Update** My future brother in Law has reported that the MAC version of the green pois0n mod worked just as well and as easy on his intel based MacBook. We had gotten together earlier last week and had a heck of a time trying to get SeasonPass to work. I believe we got it working once, but I inadvertantly unplugged the power after the mod and due to the "tethered" limitation of the mod, bricked the ATV2 as soon as it came back online.