Still a lot of question marks here. Harbaugh is starting to look like a guy who wears out his welcome very quickly. His pattern seems to be: come in, make early improvements, plateau, then leave for another job in the wake of grumbling about his approach. Considering what Michigan has gone through with coaching changes, they can't afford to miss on another hire. They need a long-term guy to bring stability back to the program. That doesn't sound like Harbaugh to me.
Also, the $64,000 question is recruiting. If Harbaugh is not a big-time recruiter, he had better hire some awfully good assistant coaches to handle the recruiting.
This is not a slam-dunk hire in my book. It may work out great, or it may blow up in their faces. To Be Determined........