The iPhone Dev Team has released redsn0w 0.9.13dev1 which will jailbreak iOS 6. This version of redsn0w only supports the iPhone 4, iPod touch 4G, and iPhone 3GS, namely no support for A5 devices. It will be a tethered jailbreak and should only be used by developers as it's a beta and you'll most likely run into issues.
A tethered jailbreak for iOS 5.1 is now currently available for the original iPad and the iPhone 4, and earlier model iPhones. (If you have an iPhone 4S or iPad 2, don't attempt to update to iOS 5.1 and jailbreak, it won't work.)
While jailbreaking already provides tons of functionality, there's still room for improvement and expansion in 2012. Last year I did a list of jailbreak concepts Apple should implement and low and behold, they implemented quite a few of them. But that's part of the game. Part of what spurs more innovation is creativity and pushing boundaries. And at the end of the day it's really the user base that is the most useful when it comes to helping developers out. They can't create it if they don't know we want it. So this is our list of the top 5 things we'd like to see jailbreak accomplish in 2012.
Heard about the untethered jailbreak for the original iPad, iPhone 4, iPod touch 4, and older models running iOS 5.0.1 and curious how to use it on your own device?. This jailbreak won't yet work with newer, Apple A5 chipset-powered devices, namely the iPhone 4S or iPad 2, but if you own anything earlier, you're in luck.
If you need to tethered jailbreak iOS 5.0.1 via redsn0w you can now do so without having to manually point to iOS 5.0. The Dev-Team has updated their redsn0w tool to offer native support for iOS 5.0.1. Other notable changes include full support for the newer 8GB iPhone 4, iBooks issue fixed, custom IPSWs for 3GS owners without blobs, and more.
The iPhone Dev-Team has gone ahead and updated UltraSn0w as planned with full support for unlocking your iPhone 3G, 3GS and iPhone 4 under iOS 5.
UltraSn0w 1.2.4 is available in Cydia now and supports iPhone 3G and 3GS basebands 04.26.08, 05.11.07, 05.12.01, 05.13.04, and 06.15.00. Remember, If you're trying to unlock your iPhone 4, the only baseband currently supported by UltraSn0w is 01.59.00.
iPhone Dev-Team member MuscleNerd has gone on the record stating a port of Siri to other iOS devices outside of the new iPhone 4S will require piracy, and likely won't ever see the light of day as a consequence.
Anyone hoping for a "port" of Siri from iPhone4S: pending a very low-level A5 exploit, it likely can't be done without piracy