i have been waitlisted as well, i was sure that i will be rejected so i'm happy to know that at lease i'm waitlisted
don't be upset! look at the positive side, they consider you as a qualified candidate
don't ever give up, you don't know what will happen
i sent a polite email with some questions, they basically responded with an advice to wait patiently
they will contact you if they need any further information from you, so the only option we have is to wait and see