A Jailbreak for iOS 5.01 on A5 devices (the iPad 2 and the iPhone 4S) has been released today. If you didn’t yet update your devices to 5.01 now is the time because Apple is expected to release iOS 5.1 very soon.
The exploits that are used to make the jailbreak possible on iOS 5.01 have been fixed in iOS 5.1 and will not work.
Although you can save your SHSH blobs for 5.01 it’s not possible to restore to iOS 5.01 on the iPhone 4S and the iPad 2 3G using Tiny Umbrella.
The current jailbreak (Absinthe) is Untethered and only available for Mac OS X for now.
If you want to unlock your iPhone 4S than you are advised to the 9A405-version of iOS 5.0.1 since this version is running on an older baseband for which an unlock possibility is expected.