Any undefeated BCS conference winner plays for the national championship. That's just math. They rewrote the equations to ensure that when Auburn didn't make the NC game after going undefeated playing patsies. The only way an undefeated BCS team doesn't play for the NC is if there are 3 undefeated BCS teams.
"there’s not a lot of difference between the ACC and the WAC or Mountain West except for that glamorous 'BCS conference' moniker and the resulting Orange Bowl affiliation."