Last week, a seasoned developer managed to jailbreak iOS 6 less than a day after Apple's WWDC keynote--although it certainly wasn't ready for the public. After a week of waiting, the iOS 6 beta is now officially jailbroken.
This tethered jailbreak uses the newest version of Redsn0w (0.9.13dev1), and it works on iOS-based contraptions that can be hacked with limera1n and have an A4 chip. This means the jailbreak will only run on the iPhone 3GS, iPhone 4, and fourth-generation iPod Touch.
If you can jailbreak your iGadget, be aware that there are a couple of limitations. For instance, the Cydia store won't work with iOS 6--though an update to add iOS 6 compatibility is on the works. Hacktivition--a component of the Redsn0w jailbreak that lets you use the iPhone on unofficial carriers--is also not supported. Most significantly though, this hack will only work for those signed up as an iOS developer with Apple.
For a majority, then, this jailbreak will be worth a miss. However, the current hack is mainly aimed at developers wanting to tweak their apps and iron out any bugs, so there is a possibility of a more widely available update in the future. Of course, even if this is the case, you will have to manually manage the jailbreak rather than using Cydia--if you aren't sure how to do that, then you may want to hold out until the software is compatible with iOS 6.
If you want to attempt the jailbreak yourself, go to Redmond Pie for full instructions.