Unless things have changed for this year, applicants are seldom rejected post-interview. The only time that's the case is if someone is particularly concerning.
However, applicants that are continued really are reviewed regularly. There is typically a slow period until about April or so when movement of continued applicants usually picks up. It's a year to year thing, though, so sometimes there may be no movement at all while other years there may be lots of movement.
Again, though, this is based on previous years and may not be accurate as things have changed quite a bit with the new admissions director.
Is there a distinction, besides the name, between continued and waitlist? I'm under the impression that there have been enough offers sent out to fill the class, and now they're just waiting for people to give up their spot in the class before extending offers to continued candidates? All this ambiguity is killing me. I realize the official waitlist isn't formed until June--just wondering if continued is a de facto waitlist in the mean time.
And by the way thanks for all your input in this thread--it has been really helpful.