If undefeated, they are guaranteed the Rose Bowl or a shot at CFP.
If not undefeated they still have a shot at the Rose Bowl if they win the PAC 10.
If they do not go to Rose Bowl, probably go to same bowl regardless of BYU win or koss.
The only thing a loss to BYU will do is keep them out of CFP I'd they are undefeated in all other games. All other bowl options are probably not impacted.