With the released of IOS6 imminent, iPad2 and iPad3 owners have limited time left to save their SHSH Blobs for 5.1.1 if they haven't already done so via TinyUmbrella or Cydia.
Whilst there is no guarantee that 5.1.1 blobs will be of any future use, it is still recommended best practice to take a few minutes of time before IOS6 is released to save them away for a rainy day! The same situation existed for 5.0.1 blobs, and one day, out of the blue, a downgrade was released from 5.1 to 5.0.1 to jailbreak the iPad2, provided folks had saved their blobs of course
We have a tutorial on the process here - HOW TO - Save your SHSH Blobs with TinyUmbrella
and some background on Blobs here - http://www.ipadforums.net/ipad-hacki...ed-2012-a.html
Remember, once IOS6 is released Apple will quickly (typically within 24 hours) stop providing blobs for 5.1.1. Once they do that you will never have the opportunity to save them again!