Here's a little tidbit about the power of mid-majors

In the six Final Fours from 2006 to 2011, the CAA (two) and Horizon (two) have each sent more teams than the Big 12 (one). The Horizon also has more Final Four victories (one) in that span than the Big East, which hasn't won a game at the event since Connecticut's 2004 national championship.

Link

Of course, the one Big 12 entry did win the whole enchilada, Kansas in '08.

I would add that the ACC has had 3 FF entries (UNC x 2, Duke), 4 FF victories, and 2 titles in that stretch (UNC '09, Duke '10).