[Not that we've ever done it ourself, but a tethered jailbreak can be a pain in the ...]
In a blog post, hacker pod2G announced that the Chronic Dev Team and iPhone Dev Team, have released the new jailbreak. It's based on earlier work done by pod2g.
The new version of “redsn0w” is compatible with the iPhone 4, iPhone 3GS, iPad and third and fourth-generation iPod touch devices. If users are already running a tethered jailbreak, they can upgrade by using a utility called "Corona" that's currently available in the Cydia appstore for jailbroken devices.
Yes, we're unfortunately still waiting for the iPhone 4S and iPad 2 jailbreaks, but hopefully those will come, and before Apple releases iOS 5.1, which has already reached Beta 2.