Same story here, I had interview and waitlisted...
And I agree with nightmoves, this waitlist thing smells like a polite way to say "You are rejected."
Coz I've never seen anyone got rejected after their interview with UB...
I think once you had interview with UB, it's either Acceptance or Waitlist...
But keep your hopes up...
It's extremely rare case but I know someone got off the waitlist in April...
I'm crossing my fingers for that....