I actually heard this same scenerio mentioned several weeks ago when Ohio State was still in the mix to go to the Sugar Bowl.
Now, THAT would be $crewed up!!!!!
Assume that Oklahoma and LSU play in the sugar bowl, and it's a dreary 6-3 game with LSU winning. USC blows out Michigan 35-3. LSU would be #1 in the coaches poll, they would pick USC #2. Then it would be flip flopped in the writers poll. LSU would still be the "official" champion, but not many people would be happy. Best scenario for the college people is that whomever doesn't go, loses in the other game. Otherwise, it's going to be very controversial.