Just speculation from what I've been reading. That's why I said rumors. I'll try and hunt down what I was reading again and post it. But again my buddy who preordered and registered his code on October 30th is in and playing. Also another friend of ours says he is playing and he registered his code on november 3rd. We're waiting on him to prove it by logging into the server and whispering the guy next to me. I'll just bet, Nov. and Dec. is tomorrow!
But I know now just from lookin at the official email thread that a 5th wave has gone out. Yesterday when they posted the final wave had gone out on that thread they also posted that it was the last wave of the day. So judging by that we are seeing a 5th wave go out!