I think this cycle has been instructive, the thing I've seen is that
1) there's a lot of really strong applicants in rads as well as other top specialties, although rads appears to select for board scores, research, and not necessarily the most well-rounded applicants, although I have met some pretty awesome people on the trail.
2) 2012mdc, I don't know if you've seen this too, but at the top programs, almost all of the applicants are from name schools. In Seattle this last weekend every single applicant was from a top 25 rads program and the majority were from Washington, ucsf, Stanford, or Hopkins. This was true at most of the top "national" programs, but more regional powerhouses had more of a regional feel of the applicants/residents.
3) you see a lot of the same people on the trail, it's sort of fun, I've seen the same guy at three different programs in diff regions of the country.
4) at least in rads, interviews are super chill and more to screen out weirdos and gauge interest. That being said, I've heard from some people that if you have deficiencies in your app, some PDs ask about them, I haven't seen that though so maybe they screen for their "red flags" prior to the interview. In any case, it's sort of a humbling process; I have interviews from about half the programs I applied to, which I guess is considered successful. There def are some "wtf" moments though.