This post is to remind users to backup their SHSH blobs by using TinyUmbrella.
Please refrain from updating.
A5 USER WARNING:
Even if you cache your SHSH blobs for your A5 devices with TinyUmbrella, they will not be usable at this time. A loophole or DFU/iBoot level exploit is needed to overcome the iBEC apticket requirement upon restore.
Update: As of March 8, 2012 at 6PM [EST], Apple is no longer signing 5.0.1 (9A405/9A406)