Dev Team has released iOS 5 beta jailbreak through redsn0w 0.9.8 beta 1 tool. But only the devs can do it at the moment. Once iOS 5 is released publicly, this will also be public soon.
Download Redsn0w 0.9.8b1 To Jailbreak iOS 5 Beta
Download Redsn0w 0.9.8b1 To Jailbreak iOS 5 Beta