Big deal. High school seniors commit and decommit regularly.
GNB, here's a question for you. Was OSU overrated last year and did it play the same "very weak schedule" last year? Your answer is probably "yes." What difference did it make last year? Absolutely none. This year, like last year, the national championship will again be determined on the field not based on the conventional wisdom and groupthink of football writers and broadcasters.
Now, as far as Harbaugh is concerned, here are some numbers for you. 3, 4, and 4. Here are some teams for you. San Diego State Aztecs, Stanford Cardinal, San Francisco 49ers. How long do you think Harbaugh is going to stay in Ann Arbor? He inherited Hoke's players (I..e, some good talent). He only had a 12 or 16 player recruiting class this year. The jury is very much out on the long term impact Harbaugh is going to have at Michigan. But at least in the short term he might help improve OSU's strength of schedule so that you can be satisfied. You can then move onto to the next school for criticism so that you don't have to think about your "I got a 'not recommended for human consumption' substance over the counter and it put 43 pounds of muscle on me but it was all just an unfortunate mistake" QB and your other criminals at felony U.