The wait for an untethered jailbreak for the iPhone 4S and iPad 2 running iOS 5.0.1 is finally over, with French hacker Pod2G and the Dev Team hackers releasing a jailbreak tool called 'Absinthe', which is indeed a form of 'greenpois0n'.
iOS 5.0 received a generally good reception from iPhone owners. Two particular issues were reduced battery life, and the absence of Siri for the iPhone 4. Apple's done something about one, but not the other.