Three negatives of OU staying in the Big 12:
1. Less revenue—Without a doubt, the Pac-10 will draw in far more revenue for the Sooner program than the Big 12 will. In fact, the figure is practically double, if not triple the amount of revenue. Currently, OU makes somewhere between $7 million to $10 million with TV revenue, and the Pac-10 expansion could increase that to nearly $20 million, reports indicate. So remaining in the Big 12 would be devastating in this regard.
2. Less exposure—It seems like the Sooners get plenty of exposure as is, but consider the TV markets of Los Angeles, Phoenix, Seattle and San Francisco consistently broadcasting OU games. Now, think about the fact that OU won't be exposed to recruits in the same way if it remains in the Big 12.
3. A worse power alignment than there already is—Assuming Nebraska is bolting, it is real simple where the power is. All the quality football programs (i.e. Oklahoma, Texas, Texas A&M) are in the Big 12 South. And most of the basketball power is in the south as well, with the exception of the team with the biggest tradition in the conference, Kansas. They are the only truly competitive unit in the north, however, so power is a real problem. Why would OU want to play teams in the Big 12 North that are much less competitive for the most part than those in the Pac-10?