The most important question is why would he leave when Saban has, at absolute most, only 5 good years left before hanging up the spurs?

We are in great shape to have the most stable program in the West when it happens. OM will still be in shambles and Ark, LSU, Auburn, and A&M are all extremely likely to have major coaching turnover within the next 2-3 years. My guess is at least 3 of those 4 will fire their head coach over that time period with one in Sumlin already being a sure thing. Great opportunity there to win bigger than ever. Maybe the best one that Mullen will ever have.