Earlier today a popular jailbreak developer, chpwn, tweeted out a screenshot of an iPhone 5 running iOS 6 with Cydia installed.
Taller screens like Cydia too. twitter.com/chpwn/status/2…
— Grant Paul (chpwn) (@chpwn) September 21, 2012
At the moment there is no further information on whether or not the jailbreak will be released publicly any time soon. If there are any updates, you can stay up to date with the latest jalbreak news here.