Prolific iOS hacker pod2g posted a video of a jailbroken iPhone 4S running iOS 5.0.1 to his blog. The video showing a clean reboot without a USB connection to the computer — aka, "untethered" — was made by Chronic Dev Team member DHowett, an illustrious iOS developer in his own right. Pod2g says "only a few to wait now" which is a good sign that an untethered jailbreak for the iPhone 4S and iPad 2 is very near indeed, and about to join the untethered jailbreak released for A4 devices on December 27th.
iPhone 4S jailbreak demonstrated on video
iPhone 4S jailbreak demonstrated on video/
iOS 5.0.1 jailbreak demonstrated on iPhone 4S. Release expected soon.