I also withdrew my application... After being waitlisted I sent the school my withdrawn and got the following automatic response:
"...Being on the waitlist requires a great deal of patience and, historically, we do not see movement from the waitlist before spring and into summer. Any candidate who maintains an active candidacy on the waitlist will be reevaluated for admission at the end of the admissions cycle (late May into June/July)...."
So, to all waitlisted: hang in there, use the second round to apply to other schools and good luck!