Moving my response from NFL thread to here:
Late response, but I think the consensus (among my friends) is Pete has to go. It's a somewhat similar trajectory to Holmgren: brought the team to the highest of highs (at their respective points in team history), continued to make playoff appearances, but eventually their philosophies got outdated, drafted poorly, traded poorly, and they fell off. Holmgren went 4-12 his last season (then Mora 5-11, I think). I think we've reached the end of Carroll's run.
The Wilson situation is more tenuous. He's not the same player anymore. Teams aren't afraid of him. He doesn't run, and his line continues to suck, so they can blitz at will or just lay back in coverage. They can't get as much as they could have a year ago.
Harbaugh burns out. I'm shocked he's been at Michigan this long. But, at this point, why not take a shot? Who else are they going to hire? The pool is thin, especially when it's all retreads.