With 12 CUSA teams and 11 MWC (assuming BYU stays and FSU and Nevada join, as reported) teams, the math suggests a 24 team arrangement, called CUSA, which could now become true to its name. You can assume that no one is kicked out.
So, by adding one more team (i.e. Temple or La Tech), you have two 12 team conferences with an automatic BCS play in rights from a merged Championship game. Whether you have separate conference (or division) championships is to be determined. Better yet, how about 4 Divisions of six, then round robin to Championship Game and a BCS spot.
The value to current BCS is enhanced by making Cotton Bowl a BCS bowl, permitting another BCS team to make it as well, in addition to MWC/CUSA champion.