Early this morning, the iPhone Dev Team showed off a quick video demonstration for something called backup plan which doesn't waste exploits but this method requires more time to make it work on all devices on iOS 4.2.1.
iCykey: @comex I want a 4.2.1 untethered jailbreak for christmas :PAnyway, comex has confirmed that he will release his hacks to untethered iOS 4.2.1 jailbreak for Christmas so that means we'll see iOS 4.2.1untethered jailbreak before the end of 2011, and yes! in less than a month. I recommend to follow us on Twitter or get on Facebook to keep yourself updated with these bunch of good news about iOS 4.2.1 jailbreak.
comex: @iCykey you'll get it.