With every major new release of iOS comes a period of anticipation for the next release of a stable jailbreak courtesy of the iPhone Dev Team… and the good news this time around is that it doesn’t look like iOS 4.2.1 set the Dev Team back very far at all.
As the Dev Team explains in their latest blog post, iOS 4.2.1 is just as jailbreakable as any past version on the iPhone 3G, older iPhone 3Gs and non-MC iPod Touch second-gen models, thanks to a combination of the original pwnage2 exploit, the arm7_go exploit, 24kpwn, and limera1n.
Less jailbreakable right now are all the more recent devices, including the third and fourth gen iPod Touch, the iPhone 4 and the iPad: while these devices are still jailbreakable, right now, it’s a tethered jailbreak, meaning that every time you want to reboot your device, you need to connect it to a computer to do so… although Dev Team member Comex is already hot on the trail of remedying that.
Basically, since Apple didn’t close geohot’s limera1n exploit at all this go around, iOS 4.2.1 is jailbreakable pretty much out of the gate, although you might have to tether your device for reboots on occasion until the Dev Team works around the new security measures Apple did introduce.
As for ultrasn0w carrier unlock, the Dev Team says it’s too early to say when that’ll be coming, but initial ganders at what Apple has changed with this version are very promising. All in due time.