I talked to Carmen a while back in February. She said they would be done interviewing at the end of February and that all letters would be mailed out during the first week of March.
After my little chat with her, I received an acceptance letter two days later. My friend just got his waitlist letter about 3 days ago, so I think the mail is arriving as we speak.
They're pretty hush-hush about their waitlist this year because Carmen wouldn't tell my friend his rank on the waitlist either... =/