We had already covered downgrading procedure for iPhone 4, iPhone 3GS, iPhone 3G, iPad and iPod Touch but the last thing missing was iPad 2. TinyUmbrella has been recently upgraded to 5.00.08 which gives you an option to to downgrade your iPad 2 from 4.3.4 or 4.3.5 to 4.3.3 if you have saved your SHSH blobs.
As you are already aware that Jailbreak available on 4.3.4 and 4.3.5 is tethered so there is always a wish to return to 4.3.3 to have untethered Jailbreak.
This thing has been recelty confirm by @notcom
This is not an addition however the same was already available but on downgrade iPad 2 used to go into Recovery Loop which has been recenlty fixed in this update of TinyUmbrella 5.00.08. Secondly it used to give 1013 error during recvoery which has also been fix.
So what are you waiting for download TinyUmbrella 5.00.08 from the links below,