Today the Dev Team rolled out a beta release of redsn0w (v0.9.6). Currently, it only supports third-gen iPhones and second-gen iPod Touches running iOS 4.x, and only runs on Mac OS X x86 (the Windows version is still Too Buggy for Prime Time). The update reveals no new exploits to Apple. The Devs also caution:
IF YOU USE THE ULTRASN0W UNLOCK, PLEASE WAIT FOR PWNAGETOOL TO SUPPORT 4.1. DO NOT USE REDSN0W. That's because to use redsn0w at 4.1, you need to already have updated to official 4.1 from Apple. If you do that, you lose the ultrasn0w unlock (possibly forever).
Keep in mind that iPhone 4.0 jailbreak is moving along as per Dev Team.
[Via the iPhone Dev Team Portal]