Let them say that. The AP has been awarding the "national championship" trophy for longer than most of them have been alive, and they never gave it up when the BCS was formed.
The AP even refused to allow the BCS to use its rankings in the formula this year.
A USC victory would be a third consecutive national championship. Not an undisputed one from a couple of years ago, but the upstart BCS is still trying to figure it out.