Unfortunately, I think that it's going to take a while for the welcome letters to come out mainly because there will be at least a million letters to send out and they can't afford for the Beta site to crash on the first day. According to the congratulatory letter, it should come between tomorrow and Sept 30. Here's hoping I don't have to wait until Sept 30th because that's just one day before everyone else can get in and if that happens then playing the challenge would have been all for nought. Crossing fingers!!