Apple has pushed it back to squash a problem with WiFi that was found in 4.2. There's no firm release date that I've heard other than "end of November", though that was pre-bug.
Apple just likes to make crap excuses... and the "Day You Will Never Forget" I wont forget that day... being angry at apple...
I sense someone wants the Harry Pottter game that just came out ! Yep, it's frustrating - the newly released GM (a week ago) already addressed that iPad/Wi-fi issue, so now it's a matter of a bit more waiting.
Do what I did: Download the iOS 4.2 GM Seed and Shift + restore your iPad in iTunes. People say you need a paid developer account for it to work but I had no problems.
I have to admit I am getting a little irritated as well, especially since there are more and more games requiring the new os.