FYI -
Having reviewed some of last year's threads, I found that Michigan leaves most applicants files open - without rejection - until January. They leave some in-state applications open into February. See
here.
Another person said that interviews occuring in early January were already pretty much exclusively for the rights to be on the
wait list.
Another guy said that last year's last interview date was 3/12, and that the last invites had gone out by
2/17.
This thread backs up the earlier statements. It looks like a lot of people got rejected in the last week of January/first week of February. They say the last interview invites were going out the last few weeks of January, the last date was also stated as 3/12.
To top it all off, UMIch takes a huge number off their wait list - someone said almost 40% of the class. According to
this thread the waitlist last year had 350 people in it, was split into 3 tiers with the top tier being virtually accepted, and it didn't really start moving until the end of May. Someone else in the thread said it's common for people to be accepted at UMich the week prior to orientation.
So, to sum up, UMich has one of the longest acceptance processes in the country.