Dantonio has reached his acme at MSU, imo. He's done as much there as one can do in today's college football climate, and if he is set to retire at season's end, then it'll be because he knows there is nowhere to realistically go but down in East Lansing. Knowing that national titles are the goal for every mid-level and up P5 program, and knowing that it's highly unlikely he can win one at *ichigan State, I can see the timing being right to step away after this season. I hope not, because he's a very good coach/player developer, and a solid representative for the B1G... but the expectations and the reality simply don't align at these programs on the periphery of being a major player, and MSU is, and has almost always been, a program on the edge of where programs like Ohio State, Alabama, Oklahoma, Notre Dame, and yes, even ttun reside. MSU, UCLA, TAMU, etc., are programs who are historically on the outside looking in, and breaking through to that next and highest level is difficult. Fisher might do it at A&M because he's a very good recruiter, but Dantonio isn't and he never will be.
In addition, Fickell going there doesn't bother me for two reasons... first, and despite popular opinion on here, I don't think Luke Fickell is Ohio State head coach quality, and second, if I'm wrong and Fickell is an OSU caliber HC, it won't matter where he when the job next opens, because he'll leave wherever he is in a heartbeat to come home.