I received it yesterday or the day before. I'm in town, so mail gets to me quickly.
I didn't look at it much yet. I seem to remember it being just a form letter thing. You fill in your name and address or something like that, and sign it at the bottom. They also included a letter saying you need to send this in, and that they don't care when it is post-marked, but when it is received. So send it in quickly, as once the deadline arrives they plan on offering your seat to someone on the waitlist if they haven't gotten your letter.