I've been under review for a month and a half and my stats are definitely better than some of the other people who got interviews. I don't have the 38/4.0 required for an automatic interview but I'm close (>35 and >3.9) and for such a stats oriented school I'm surprised I haven't been put on hold then.
The only think I can think of is that Michigan doesn't like my state of residency and/or my undergrad institution.
Have you noticed on their profile page pretty much all the students come from certain undergrad schools:
http://www.med.umich.edu/medschool/admissions/apply/profiles.html.
Guess because my undergrad school wasn't in Michigan and wasn't Harvard or Yale I'm out.