My idea on how to fix the BCS is a variation of a +1 format. I have given up on a tournament format, besides I like all the bowl games.
You play your BCS games on Dec 31, Jan 1, Jan 2 like most are anyways. Then you take the teams in each of games and do another rankings. So there would only be 8 teams ranked. Then you take the top 2 teams and play a National Championship Game the next weekend. You still keep all your traditional match-ups, and bowl games. You might need to add a 5th BCS game I would say you add the Cotton Bowl then rank the 10 teams. Some would say that that is unfair to the Big 10 and Pac 10 because they can't both be in the NC game but they both could because the voters can, for example USC and Penn State in the NC game.
But what you have to remember is that even they have a playoff the #5, #9, etc team is always going to be left out just look at March Madness some team is always left out.
I think this is the most workable idea for the BCS.