With Neuheisel on the hot seat, I'd think that UCLA would be appealing for Peterson - he stays out west, big name school, and USC is bound to feel some sort of effect from their issues. The timing seems right.
But I don't know if there's a story as to why he didn't go there a couple years ago when they had an opening. Was it an issue with the school or did he just realize that he had a better situation with the players he had in Boise? If the latter is about to change with upcoming sanctions, it might be time to get out.