I'm not sure that a new umbrella organization, similar to the NCAA in terms of revenue sharing, oversight, and operating multiple championships, but only for 64-70 schools, would be feasible. The big problem with this is that it would be hard to get those schools within 4-5 conferences to agree on basic rules. Without precedent, whose to stop the SEC from insisting that there are no minimum academic requirements for athletes. John Infante of the Bylaw Blog wrote a great article on the subject about a month ago. For instance, why would a new organization pay so much money to fund championships in money losing sports when there's nothing compelling them to do it. This is after all, about making money, and the other sports do nothing but drain money for marginal benefits. I think that many schools are aware that the time, efforts, and costs in forming a new organization are great, and it may not happen for several years, if not decades. In the meantime, with the new contract that the Pac-12 just got and the emergence of the Longhorn Network, I don't the Pac-12 trying to jump to 14 or 16 right now, and even if they did, I don't see Texas jumping on the change if they have to fold in the Longhorn Network to the new Pac-12 regional networks.
For the immediate future, I see the SEC taking A&M plus one more from the Big 12 or ACC. BYU will replace A&M, and the other school will be replaced by poaching one team from the Big East.