With the release of Firmware version 4.2.1, rises the concern of jailbreaking and unlock compatibility. If your waiting for an unlock, wait for the ability to create custom 4.2.1 firmwares. If you’re not an unlocker, then there is good news for jailbreaking your devices.
Those of you who own an iPhone3G, older iPhone3GS, and non-MC iPod touch 2G will benefit the most with this news from the Dev-Team. They explain that due to a combination of the original pwnage2 exploit, the arm7_go exploit, 24kpwn, and limera1n, your device is “just as jailbreakable as ever.”
For those of you with the newer devices, geohot’s limera1n exploit, will actually work just fine. The unfortunate news is that, as of right now, the 4.2.1 jailbreak is *tethered* on new devices. What is a tethered jailbreak? "A tethered jailbreak means that each time your device loses battery power or needs to be rebooted, you must attach it to a PC or Mac to boot into the jailbroken state."
@comex, the guy behind creating tether hacks, is working hard as usual on an untethered 4.2.1 jailbreak, but unfortunately at this point, it will require you to have your 4.1 SHSH blobs in order to use it.
So when does all this 4.2.1 jailbreak action happen? Well if you’re a JB developer or tinkerer, you’ve already probably used the redsn0w mentioned in our last post to jailbreak 4.2.1 and at least get SSH working. But beyond that, there are still some last minute issues with MobileSubstrate and comex’s kernel patches that are being fixed. We’ll tweet and post a blog update when it’s all available (we hate to give ETAs, but barring any unforeseen problems, probably later today).
ultrasn0w unlock: After redsn0w is officially released with the new Cydia and kernel patches, we’ll be able to assess the unlock situation. It’s already looking very promising though, so expect the unlock for the 3G and 3GS to be coming this week. The i4 unlock is taking more effort though, and no further concrete info is available about that yet.