How can I do an unthethered jailbreak for iPad Wifi running iOS 4.2.1 if you do not have older SHSH? How can I jailbreak iOS 4.2.1 (unthethered) if you do not have older SHSH?

Currently I'm looking for this only for my iPad WiFi, so no baseband. 

If there are not solutions yet, do not post anything.
Greenpois0n rc5 Has been released and can do an untethered jailbreak on 4.2.1 without older SHSH blobs.

http://www.greenpois0n.com