Dev-team and Comex has confirmed that untethered iOS 4.2.1 jailbreak will be out before Christmas 2010. First MuscleNerd came up with a video demonstrating untethered iOS 4.2.1 jailbreak on iPod Touch 4G.
According to MuscleNerd, it’s a backup plan for untethered iOS 4.2.1 Jailbreak because comex is working on a more extensible one, but this method is also generalizable. This method Uses iOS 4.2 beta 3 SHSH blobs Cydia kept for you.
Got “backup plan” for untethered 4.2.1 JB working (video coming up). Uses mysterious 4.2b3 hashes Cydia kept for you [Source]
(It’s a “backup plan” because comex is working on a more extensible one, but this method is also generalizable) [Source]
Later, Comex, the dev behind Spirit and JailbreakMe, confirmed that the userland untethered jailbreak for iOS 4.2.1 will be released before this Christmas. So expect the iOS 4.2.1 untethered jailbreak released within next couple of weeks.
iCykey: @comex I want a 4.2.1 untethered jailbreak for christmas 😛
comex: @iCykey you’ll get it.
*** This will jaibreak all iOS 4.2.1 devices UNTETHERED!
We will update you as the more info comes, Stay Tuned!