I called today and while the admissions lady was very nice and supportive, she really didn't have any words of wisdom to impart. There were just the same generic comments about "interviewing until the middle of April blah blah blah". I did ask her, though, about how much time they give students before the interview. She said if I was out of state, I should expect about a month between notification of an interview and the actual interview. In state.... she said it could be as close as a week. So any out-of-staters, if you haven't heard from them by mid-March, that might be it. And us in-staters: guess we have until around April 10th or so... I really would like a shot at this school; the only thing keeping me from going completely insane is that I have other admissions offers.
Another possibility: all our letters got lost in the mail?