I think it is more and more likely that that Big 12 conference WON'T split up. OU and Ok. State might decide to leave, but I think Texas still tries to keep it together. And I think they will find a lot of support from the likes of Texas Tech, Baylor, Iowa State, etc. The television contracts are locked in until 2014 (ESPN/ABC) and until 2025 (Fox). I think the networks will have a hard time backing out on those contracts, as long as the Big 12 fields a conference.
I look for the Big 12 to make a play for BYU, TCU, Houston, SMU, and who knows who else - perhaps Tulsa, Louisville, Memphis, etc. With the kind of money the league has in it's coffers it will be easy to attract these teams to join.
I think Texas will prefer to rule the roost in a ****** conference, which maintains an automatic BCS qualification, with it's own television network, etc. rather than give all that up to join the Pac-12/16.