Corona

Corona is a Cydia package from the Chronic Dev Team on Saurik's repo. It uses pod2g's racoon string format overflow exploit and an HFS heap overflow to untether iOS 5.0.1 on previously-jailbroken devices. Alternatively, users can also re-run the iPhone Dev Team's redsn0w 0.9.10 to untether their jailbreak with the same exploit. The name is an anagram of the aforementioned racoon software.

A5 Jailbreak
According to pod2g's blog, he was having problems with the app sandboxing system used on the A5 processor in the iPad 2 and iPhone 4S, so he got planetbeing, MuscleNerd, Joshua Hill and saurik, dubbed the "dream team", to help to fix it. A release date still hasn't been revealed, though.

Changelog

 * 1.0-3 was updated by Saurik to enable redsn0w 0.9.10 users to update the jailbreak through Cydia.
 * 1.0-2 fixes a bug that caused launchctl to not start daemons on-demand.
 * 1.0-1 is the initial release of the jailbreak.