Harbaugh is an insanely competitive guy and I think he's got unfinished business in the NFL. I agree he's probably going to need more time at Michigan, since it means so much to him and all, but IMO if he wins it all this season he might be willing to entertain a good offer. And Stan and the Rams would be the kind of offer I think he would at least consider. He'd have complete power, the big contract, and a roster that is better at some key positions talent-wise than what he inherited in SF, and all of it under an owner that will let him do his thing.
So personally I'm pulling for Michigan to win it all this year.