I like AU with the points and also like the under.
I think AU will keep it close and under for a number of reasons. I do not think USC's offense will be any different then in years past. Carson Palmer seems destined to underachieve.
AU's offense relys on Carnell Williams. He will get the ball around 30 times. This will eat up time and help keep the scoring down. AU's QBs which are not great are not being asked to win a game. They are being asked to not lose a game. This means that there will be a lot of short high % passes that again will keep the clock moving and keep the game lower scoring.
Also AU does have a good defense. Their LBs are some of the best in the country. Their defense should keep AU in this game and possibly upset USC.
For all of the foregoing reasons, I really like AU and the under. I just hope that AU keeps it close and does not pull the upset.