While I'm sure Greg will find a way to accomodate everyone who signs up for the Vegas NFBC, convention floor space at the Rio is limited because of all the World Series of Poker sattelites.
If you want to draft in Vegas don't delay in signing up. The Rio draft room has space for about 8 leagues and 6 are filled already so you might not want to wait for that income tax refund before you sign up. The sooner Greg has an idea on the final numbers the better chance he has at finding extra space. Don't get shut out. NOW is a good time to sign up.