Untethered iOS 4.2.1 Jailbreak for iPhone and iPad Delayed, Backup Plan in the Works

A couple days ago, we mentioned the fact that the Dev-Team was about to release its new untethered iOS 4.2.1 jailbreak for iPhone and iPad on or before Christmas day. Less than 24 hours before the deadline, it seems less and less likely that the jailbreak will be launched on time. Comex, one of the most prominent Dev-Team members, sent a tweet on the 22nd announcing that he might miss his Christmas deadline – he hasn’t been heard from since then. For now, iOS users running 4.2.1 have no choice but to use some combination of redsn0w, pwnage2, arm7_go, 24kpwn, and limera1n to jailbreak their device. Another alternative is to keep iPhones, iPod Touches and iPads on an older release of iOS. When released, the new untethered jailbreak should work out of the box, without the need of other exploits.

If you cannot wait for the update to be released, you can always use the Dev-Team’s redsn0w jailbreak (guides are available all over the web), but you’ll be tethered. The Dev-Team is also working on a redsn0w-based backup plan, and is looking for qualified testers:
To keep things manageable, this will be a Mac-only test program. We also request that any volunteers NOT need the ultrasn0w unlock (in case things go very wrong). Right now, the “backup plan” requires that you have the 4.2b3 IPSW on your Mac, and that Cydia has your 4.2b3 SHSH hashes. Please don’t pirate that 4.2b3 IPSW! (We’re also working on a way that this technique might apply to all those with 4.1 IPSWs, but that’s not the first goal right now.)
If you’re interested, follow @redsn0w_testers on Twitter to apply. As usual, even though jailbreaking your device is considered legal, always keep in mind that Apple considers it a warranty-voiding act.