A couple of thoughts based on what has been stated in this thread already. Texas A&M sounds like a done deal, which Slive should go ahead and ink. As for #s 14-16:
Mizzou - good idea. They bring the St. Louis and KC TV markets, a good football program that has the potential to recruit and compete, they would be a good geographic fit in the west.
WV - decent idea, especially to get us to 15 or 16. They have a solid national following, and would be a great cultural fit.
NC State - decent idea, but not sure they have the fanbase to really thrive in the SEC. It would get us a NC presence however.
UNC + Duke - not going to happen. They will claim academics and that the ACC is such a strong conference, but they would not be able to compete except for basketball. This is a football-driven decision. They don't have the fan bases to support an SEC move in football. Plus they like running the show in the ACC, and would be at the bottom of the SEC every year.
Oklahoma - good idea, but sound like they are already PAC-bound. If we could get them without OK St., that would be huge, but doesn't sound like that is an option.
Texas - very bad idea. Their prima donna attitude has been the downfall of the Big12, and besides that, they like being a big fish in a small pond. Plus they aren't giving up the LHN.
B12 and BE leftovers (USF, Louisville, Cincy, TX Tech, OK St., K-State, Iowa St., Baylor) - all bad ideas. None of these schools bring anything to the SEC that we don't already have.