Notcom has released TinyUmbrella 5.10.08 which includes support for the latest iOS 5.1 for iPad 3 and Apple TV 3.
TinyUmbrella now has support for saving 5.1 SHSH for Apple TV 3 and the iPad 3 (all versions). As of now we still cannot restore them but we are working on getting that working from a bunch of angles. I’ll let you know more when I do.
Save your SHSH!