I sometimes wonder whether the thing to do is to use a +1 format that is based on the historic bowl tie-in system and that would replace the BCS Championship game with the added game.
What would happen is each bowl would still get the rights to guarantee an invitation to one conference champion with the exception that the Rose Bowl would still get the Big Ten champion vs. Pac 12 champion. The big exception is that the participating bowls/conferences would grant a waiver under the tie-in contracts so that the #3 and #4 rated teams could accept invitations to play the #1 and #2 rated teams in the bowls that have the guaranteed contracts with the conferences that the #1 and #2 teams are members of.
For example, two years ago we would have seen TCU vs. Auburn in the Sugar Bowl and Oregon vs. Wisconsin (because #4 Stanford played #2 Oregon in the regular season) in the Rose Bowl. The winners of those two games would have played in the championship game.
This would help keep the best parts of the bowl framework intact while also adding revenue and opportunity for the non-elite programs.