It's kind of funny, actually. When they put me on hold, they had asked for my Fall 2006 grades. Before I sent them anything, I got an email invitation for an interview. It was nice that I got the email after coming back from my last final (Biochem), for which I was up all night studying (the test was 8:30AM). So it was just one day out of nowhere. The same exact thing happened to a friend of mine, just about 1 month earlier.
last year i was put on pre-interview hold at suny upstate. then, i was invited for an interview in january, interviewed in february, was waitlisted in march, and was accepted off the waitlist in late may. so, yes, it does happen.