Texas has been on the record as liking 10 teams. I think, as I said in the Notre Dame thread a week or so back, that the Irish would make a feint to the Big 12 to try and freeze expansion, and that appears to be exactly what happened. Texas either fell for it, or simply used it as an excuse to stand pat. They probably looked at FSU and Clemson the same way the ACC looks at Rutgers and UConn. They don't need to add us, and if they don't add us, we may just go away on our own. If they can get ND, great, if not, they go with 10 teams, including 6 that are among the Top 15-20 programs in the country right now. Why split the playoff money 2 more ways, and why bring Clemson and FSU in if they are not a threat to make the playoffs out of a crappy ACC anyway?
I suspect that support for expansion is split, with the non-Texas schools preferring a larger conference and Texas and Oklahoma preferring a smaller one. Looks like Texas got its way.