Another thing I think should be kept in mind is how much would a conference championship have actually helped the Big 12 in this specific year?
Let's say Baylor or TCU squeak a win over Oklahoma or Kansas State (or some decent "north" team) - they still don't make it in based on how Ohio State looked against a ranked Wisconsin.
So why even bother with a championship game if it isn't going to help you?
Let's say Georgia Tech beats Florida State, Missouri beats Alabama, and/or Wisconsin beats Ohio State. All of a sudden, having a championship hurts your league's chances.
I hope the Big 12 keeps all this in perspective before looking to add crappy teams. Big 12 championship upsets have burned them in the BCS era and there is no guarantee it would help or hurt them going forward.