The iPhone/iOS hacking community has been busy over the past few days, dealing with a newly released exploit - Limera1n - by notorious modder Geohot that prompted the iPhone Dev Team to rethink their own strategy and not waste "a perfectly good bootrom hole" of their own. It seems that work has come to fruition, too, with a new version of their Greenpois0n jailbreaking tool.
Greenpois0n is a jailbreak for the iPhone, ipod Touch and and iPad, with both Mac and Windows clients available. It's an untethered exploit, and will allow you to access third-party applications Apple has blocked from inclusion in the App Store (among other things).
There's no post on the iPhone Dev Team's site at time of writing, explaining the main changes with this updated version, but we're guessing that will come soon enough. Until then, it's a good idea to backup your SHSH hashes as per the team's instructions:
"Because the “untethered” part of this jailbreak comes from a userland hack from @comex, you should still backup your SHSH hashes for 4.1. Do this by either letting Cydia keep them (“make my life easier”), or using Tiny Umbrella. This way you can always come back to an untethered, jailbreakable 4.1 on your devices after Apple has closed their 4.1 signing window (they’ll close the 4.1 window once they push out their next firmware version). If you fail to do this and ever need to restore to 4.1 again, you can still jailbreak but it will be a tethered JB (you’ll need to connect to your computer to finish the booting process, each and every time).
And remember: you can backup your 4.1 SHSH hashes without even being at 4.1 or even being jailbroken, by using Tiny Umbrella." iPhone Dev Team