To me, I think there's a pretty clear separation between the top 5-6 teams and everyone else. I'm looking at the #2 seeds and Michigan State may be the only legit contender out of the bunch. They won the regular season and conference tourney championships. I don't see Kentucky, Michigan or Tennessee scaring anyone, although weak brackets may allow a couple of them to skate through.
I think the first weekend may be scorched earth, especially if you pay attention to the ESPN talking bald heads. They're probably just hyping it for ratings but I can't recall them calling for more upsets than they have been so far this year.
Having said all that, the Final 4 will probably look like, Marquette, VCU, Iowa State and Purdue. I can sure pick em'.