News today is that the Big East plans to go to 12 football teams. Their options are limited however with candidates like Air Force, Army, Navy, Temple, East Carolina, Central Florida, Houston and SMU. None of the teams mentioned are from Automatic Qualifying conferences, but teams mentioned (with the omission of Boise State and BYU) are among the best of the rest. If the Big 12 rest at 10, then the opportunity to take teams from the Big East, or these "best of the rest" will be severely limited.
When the Big 12 expands back up to 12, and possibly 14 (given the Big 12 currently owns the copy rights to Big 14), the expansions should consider new markets for both football as well as basketball, major metropolitan areas, and academics. While final decisions cannot come until Missouri decides whether to leave to the SEC or not, the Big 12 expanding to at least 12 now might entice Missouri to stay. Given all these considerations, the Big 12 should move now rather than later.
Which way to expand? If the Big 12 looks to improve both its football and basketball footprints, then it should look to what conference currently are strong in football and basketball. This means Big 10 and SEC for football and ACC and Big East for basketball. All these states are east of the current Big 12 footprint, not west. All these states also have higher population densities than the states west of the Big 12. While geographic continuity should be considered, there are options eastward the Big 12 should consider.
Firstly, I favor the Big 12 inviting at least Louisville and Cincinnati now. Both have reasonably competitive athletics, both have reasonable academics, and both are in complementary population markets. Both straddle the Big 10 and SEC footprints, allowing the Big 12 higher visibility in Kentucky, Ohio, and Indiana. West Virginia should also be considered if Missouri leaves and the SEC does not pick up West Virginia though this is mostly a football gain only. It is important to remember that the Big East programs needs to give 27 months notice, and may not be available for Big 12 conference play until the 2014 season.
Secondly, the Big 12 should consider penetrating the SEC territory by considering Tulane and Southern Mississippi. Tulane has strong academics and appears interested in strengthening its athletics. Tulane is AAU to replace the AAU that are lost (Colorado, TA&M, Missouri, and "Nebraska"). Southern Mississippi is strong in football, a rival for Tulane, and moves the Big 12 a bit closer to Florida, a major recruiting field and leaves option for addition of Florida teams in the future.
I think the Big 12 will lose out if it does not move ahead of the Big East. BYU and Boise State can both wait and be added later.