Definitely not Paul Finebaum, and while the career progression is somewhat normal...use success at one place to leverage a better job at another place, the jumping back and forth between college and the NFL is pretty darn rare...I honestly can't name one off the top of my head that has gone college-pro-college-pro-college. Most coaches, when they go pro, simply recycle to other pro jobs.
My point for consideration and discussion...which is going on here...is whether Harbaugh gets to a point 4-5 years into a job, gets bored, gets frustrated, gets whatever, and moves on to the next challenge. His record is always going to get him a new gig, be it college or pro. Is he getting to that point at Michigan? Heck, he might be there for 20 years...his previous record of moving doesn't suggest it is likely.