Thought this might be apt as the deluge of iPhones hits the world today. The only update I would add is that there is already a tethered but complicated jailbreak for A4 and older devices out there, but it is very un-official.
http://absinthejailbreak.org/jailbreak-ios-6-status/
http://absinthejailbreak.org/jailbreak-ios-6-status/
1st Group (A4-devices) Jailbreak iOS 6 on iPhone 4, 3GS and iPod touch 4G:
Jailbreak iOS 6 on iPhone 4, 3GS and iPod touch 4G is the simplest step that will be handled very soon. For who dont know that A4 devices can be jailbroken with the help of Geohots bootrom exploit the found on 2010. What we expect that iPhone dev-team will release new version of Redsn0w for Windows and Mac to bring compatibility with iOS 6, this may be released within few hours to days.
2nd Group (A5x-devices) Jailbreak iOS 6 on iPhone 4S, iPad 3 and iPad 2:
As usual, iPhone dream team will start their hard work to find a hole on A5 devices then upgrade Absinthe Jailbreak to inject jailbreak to iPhone 4S, iPad 3 and iPad 2. Jailbreaking such devices is not the sort of thing that can be developed overnight this may take weeks.
3rd Group (A6-devices) Jailbreak iOS 6 on iPhone 5:
Actually this is the biggest challenge for all hackers, actually we need the famous and genius hacker Geohot. But anyway, iPhone 5 is being shipped to hackers, when they got it on their hands we will feed you back with the situation.
Recommendation:
Jailbreakers should stay away from iOS 6 until finding solution for jailbreaking iOS 6.
Unlockers (Gevey SIM, Ultrasn0w, or what ever) MUST stay away from updating to iOS 6