bout an hour ago, Apple released iOS 4.1 beta 1 to developers, and you can already jailbreak it using redsn0w 0.9.5b5-5.
iOS 4.1 beta
Posted inNEWS
Apple Drops New iOS 4.1 Beta. Jailbreakers/Unlockers Beware
Apple has just dropped a new iOS beta today for developers and all iOS4 eligible devices.