Not enough spots in the BCS bowls for all three teams.
You have VT, PITT and MICH all getting automatic bids.
You have 8 spots
One of the at large teams is getting bumped out of the BCS.
Right now, expect:
Oklahoma vs USC
Auburn vs Va Tech
Michigan vs Cal
Pitt vs Texas/Utah
If Texas goes to the Rose Bowl, no chance in hell that CAL won't be playing Pitt.