It looks like we'll have the PAC-12 as an acronym for a while longer; they've passed on expansion. That renders my previous post somewhat moot, except that the SEC has some more interesting partners to work with. Oklahoma, OSU and Texas might be good ads to the SEC if they were interested, which would then leave the Fly-Over Conference largely intact with Texas Tech swapping out for Memphis.
The status quo seems unlikely to hold, since the Big East is rather shaky in its current football form. If UConn and Rutgers go to the ACC as rumored, then the Fly-Over Conference in some form is the path of least resistance for the Big 12-Big East survivors.