A jailbreak for iOS 6 is already out for all A4 devices such as the iPhone 4, 3GS and iPod Touch.  Although there is a jailbreak that will work, it is indeed still tethered meaning you have to constantly plug-in your device to a computer when booting it up.  A jailbreak for all A5/A6 devices like the iPhone 4S and iPhone 5 will not be out for a little while just like with previous jailbreaks as it is more difficult to actually break through security.

If you are looking forward to getting your new iPhone 5 jailbroken expect it to take quite a long time as the new A6 chip will be much more difficult than previous ones for hackers to get into.

Instructions for jailbreaking your iOS 6 A4 device is here. 

So what do all of you think?  How long do you think it will take for a tethered and A5/A6 jailbreak to be released.