I heard Bob Bowlsby talk about this on XM Sirius radio in his NCAA capacity, not as B12 commissioner. There is an NCAA proposal to allow a conference to play a title game with less than twelve teams and it is predicted for overwhelming passage. There is a B1G rider, however, that has the talking heads stumped. The B1G wants to mandate the conference title game must be between division champions. That means the B12, even if they play a round-robin schedule, still must have divisions. The ACC is opposed. They want to pair their top two teams regardless of division. 

I think the B1G wants this to preclude rematches immediately after rivalry week. Otherwise, you get talk of moving Michigan to October as Delaney and Brandon broached when the B1G went to divisions and were met by a firestorm.