Not available yet but looks like it’s been done. See more here: blog.iphone-dev.org Screenshots below.
Update via Brooke: :)
Well, it has been said that the Dev Team has jailbroken firmware 2.0. It is not available yet and we have definitly not tested it. So, if you are someone who wants to keep your current jailbroken applications, has an iPhone that is fake activated or has an unlocked iPhone….DO NOT UPDATE TO 2.0. As Doug mentioned earlier today in his article Warning – Read This Before Upgrading to Firmware 2.0 if you upgrade, you will lose your jailbreak and your iPhone will no longer be unlocked. If it was fake activated…it will pretty much be useless, you wouldn’t even be able to get to the SpringBoard (though, you could make an emergency call with it!). Also, even though 2.0 has been jailbroke…many of the jailbroke applications will have to be rewritten to work on the 2.0 firmware (see THIS post). All in all you may want to hang on to your 1.1.4 (or below) jailbroken iPhone for a little longer…at least until things become a little more solid and we can test them out for you. That way you do not break your iPhone…we break ours!
Note: If you have accidentally upgraded…see BigBoss’s tutorial on how to downgrade from 2.0 to 1.1.4. You can get it HERE.