Yet again hackers got upper hand on Apple by exploiting the security holes of iOS 5.0.1 and successfully released an untethered jailbreak. The new jailbreak frees your iPhone 4, iPhone 3GS, iPod touch 3G & 4G and the iPad 1 running on iOS 5.0.1. But not the iPhone 4S & iPad 2.
The reason why iPhone 4S and iPad 2 are not supported is because of the A5 processor chip used in these devices. The vulnerabilities used by hackers in non-A5 chips are fixed in A5 based iPhones & iPads. Hackers are continuing their efforts in identifying other security holes on iPhone 4S & iPad 2 but not sure on the timelines when they will be able to release jailbreak.
You can download the new untethered jailbreak from either Chronic Dev Team or The Dev Team.