Dev Team released an updated version of their jailbreak tool RedSn0w 0.9.10b7 with support to jailbreak Corona-A5 of iOS 5.0.1 over iPhone 4S and iPad 2 for Windows and Mac.
iPhone Dev Team says:
Version 0.9.10b7 of redsn0w adds a collection of useful features: It finally implements the corona-A5 jailbreak for iPhone 4S and iPad 2 devices still at 5.0.1. It can also re-install that jailbreak for those who accidentally uninstalled the untether. When stitching an IPSW, it can now grab your blobs directly from Cydia. It now shows a lot more info about your device (for instance, whether your iPhone 3G has the vulnerable baseband boot loader, or whether your iPhone3GS has the old exploitable bootrom. (And the next new feature to be added will be built-in restore support, to provide an alternative to iTunes restores.)
Download Redsn0w 0.9.10b7 for OS X
Download Redsn0w 0.9.10b7 for Windows
See also:
How to Jailbreak iOS with Sn0wBreeze
How to Jailbreak iOS with RedSn0w