First off, I would like to wish a warm welcome from the great state of Ohio to all of my new Big Ten brothers. May you have a fun and successful (but not too successful) first year in the conference.
While I am not uber familiar with the details of the USC/Bush/Mayo situation, I will do my best with the limited knowledge that I have.
While visiting my folks up in Michigan over Memorial Day weekend there was an article in the sports section of the Detroit Free Press basically telling UM and MSU fans to not get giddy re: OSU on the heels of the USC decision because OSU was cooperating fully with the NCAA investigation, where as USC did not. Take that for what you will, but I was surprised to find that position taken from a columnist of a "hostile" paper. Furthermore, The OSU case did not involve any players or staff having illegal contact with alumni, boosters or agents. (Nor, for that matter, were any issues with drugs, crime or academic integrity.) The NCAA found no significant evidence to support that anyone in the university, save Tressel, had prior knowledge of wrongdoing w/respect to the tattoos & memorabilia. He's now gone, and the school has self-imposed a vacation of the 2010 season and 2 years probation. While the NCAA has not made a ruling w/respect to final penalties, I can understand that it's hard to penalize the program & university as a whole when there was no widespread cover-up. With respect to the alleged car scandal, the NCAA apparently didn't find anything substantial enough to back up those allegations, either. Not totally surprising, as the Bureau of Motor Vehicles inquiry found that of all the alleged "deals" players got, only one car was sold at a loss to the dealer, and that was one that had been on the lot for over 150 days. Therefore, selling at a loss would not be unexpected.
In short, the NCAA found only a single violation by the coach that did not involve a broader cover-up. With respect to the players' infractions (which are a separate issue from Tressel's) there were no boosters, agents, etc. associated with those "benefits" and any compensation the players received was comparable to the market value of the items (i.e. a booster didn't pay $40k for a ring).
Hope I didn't ramble too much & made some bit of sense. Been a long day over here, & I'm heading to bed.