Just having fun with it.
This is how I like it and play in my NCAA 14 game.

ACC: Dropped Louisville, added Notre Dame. North (with Miami)/South divisions.
B1G: Kept as same
PAC: Added Nevada (north division) and UNLV (south).
SEC: Switch Alabama and Auburn with Missouri and Vandy from West to East. I understand the dominance, now in the East. :)
B12: Added Louisville, Cincinnati, UCF, and USF.
Frontier: Pioneer:
Iowa State Louisville
Kansas Baylor
Kansas State TCU
Oklahoma Texas
Oklahoma State Texas Tech
South Florida West Virginia
UCF Cincinnati

If given a re-do from the 2010-2013 cycle:

PAC: Colorado, Nebraska, Oklahoma State and Utah (14 members)
B1G: Missouri, Kansas, Rutgers (14 members)
SEC: Texas A&M, Oklahoma (14 members)
ACC: Syracuse, Pittsburgh (Notre Dame, football-only) (14 football members, 15 in Olympics)

Then, the Big 12 and Big East "merge" - Baylor, Iowa State, Kansas State and Texas Tech join Cincinnati, UConn, Louisville, USF and West Virginia to form core of a new tweener league. They invite Boise State, TCU, Houston, Memphis, and UCF to get up to 14 and maximize value. West: Baylor, Boise State, Houston, Iowa State, Kansas State, TCU and Texas Tech; East: Cincinnati, UConn, Louisville, Memphis, UCF, USF and West Virginia.

Texas negotiates a similar deal with the SEC (select football games per year, Olympic sports under SEC banner). The C7 break away anyway, reorganizing the Big East (with Butler, Creighton and Xavier); however, with all of the major conferences at 12+ members, they add Saint Louis and Dayton as well. C-USA ends up keeping SMU, ECU, Tulane and Tulsa (only losing UCF, Memphis and Houston). MWC loses TCU, Utah and Boise State. BYU stays independent, as does Navy.

There is only one move needed to get to a P4, and that move effectively leaves no more moves that add more value than they cost. If the SEC were to add Oklahoma and Texas, it would be game over. If they were to subsequently add Clemson and Florida State, they could make that a P3.

The Big XII remnants would be the strongest G6 conference, but that's all they would be, no matter whom they chose (if any) to backfill with. In the P5 now, every conference has at least two tentpole schools that any NY6 bowl would love to have. The Big Eight would have none. That's not to say they wouldn't ever have a national championship contender. There's a good chance they would. But OU and UT (even when they aren't in contention) are the Big XII's tentpoles. They have the "it factor" the bowls love.

For fun:

If the Big 12 survives:

The SEC gives up Missouri and Vanderbilt to become a 12 team league
The ACC gives up Louisville to become a 13 team league
Missouri and Louisville join the Big 12 (now 12 teams, contiguous)
Vanderbilt joins the ACC to fill Louisville's spot (ACC is back at 14)

The SEC even with only 12 teams is still the strongest football conference, and the schools richer. It's doubtful the SEC would have to take a per school pay cut and would make more per school because of dividing only 12 ways.