Just like quarterback, Michigan has two commitments at the running back position. One is Stephen Hopkins (Flower Mound, TX). The other is Austin White (Livonia, MI).
Hopkins is a big bruiser of a running back. His speed has been questioned by many, including me, but his yards per carry have jumped by a full two yards since his sophomore and junior years. He'll probably never be a breakaway threat, but he will be able to get downhill and get tough yards, particularly out of the I-formation.
White is a slasher who runs like Carlos Brown, but without the top-end speed. I've previously compared him to Jerome Jackson. He does make good cuts and can get upfield quickly after running laterally, so he fits this offense, but he's probably not a game-breaking runner like Michigan fans would like to see.
Due to the relative shortage of scholarships remaining, Michigan probably isn't going to take any more commitments from running backs, unless they're absolute studs.
Who fits that category? Lache Seastrunk (Temple, TX), Marcus Lattimore (Duncan, SC), Dietrich Riley (La Canada, CA), and Dillon Baxter (San Diego, CA). The first two have been offered but neither is interested. Riley has mentioned interest in Michigan at various times, but he hasn't visited or made plans to do so.
Baxter is the most interesting case. He says he grew up as a Michigan fan; he knows Tate Forcier and Brennan Clay from their time in San Diego, and he's interested in attending college with them, as well as safety prospect Tony Jefferson. Baxter, Clay, and Jefferson are all taking official visits to Ann Arbor this coming weekend for the Ohio State game. Baxter is a fringe 5-star athlete who's currently committed to USC but is interested in coming to Michigan as a potential . . . quarterback. Yep, he's a high school quarterback, but his future probably lies at running back.
The remaining uncommitted prospects (Cassius McDowell, Corvin Lamb, Jamaal Jackson, Marcus Coker, Tony Jones, and Brandon Gainer) are probably going to be left out in the cold or are just planning to go elsewhere. But keep an eye on McDowell, who could be a late commit if Michigan is trying to fill up their class. Michigan has been his leader all along, but he may have missed his chance to commit.