I agree that it would be nice to somehow involve the NFL/NBA in the monetary support of major college athletics in order to allow funds to be spent on academics although I'm not really sure how it would work out. As for the Big East, I think the conference might as well throw in the towel. Tulane is an absolutely worthless addition when it comes to major college football, ECU is a better choice but really won't make much of a difference. I feel like they belong in the second tier we are referring to.
I also have to agree (albeit somewhat reluctantly) that the 120something teams in FBS (D1-A) need to split into two groups, there is such a divide in the landscape of the college game now that it doesn't make any sense not to. The GAP (in resources, financial support, and on-field product) is just too great to ignore. I'm not sure how it shakes out however. Obviously; the Big Ten, SEC, and Pac 12 will still be around but I could see both the Big 12 and ACC sticking it out also. I say this because I'm not sure that there is a hard and fast number of schools that make the cut. 64 teams works out well on paper and all but realistically there might be a different numbered result, especially at first.
I say this because there are simply more teams than 64 that would probably make the cut. If we assume that all current members of the Big Ten (including the new pair), SEC, Pac 12, Big 12, and ACC remain in this top tier that already adds up to 61 teams. Adding N.Dame only leaves you two more teams if you'd like to arrive exactly at 64. The previously mentioned Boise St. and BYU would fit the bill. That leaves out any worthy additions from the Big East and some might also argue for the three service academies to be included. If those three are added along with Louisville, Cincinnati, and Pittsburgh we arrive at 70 teams making the cut.
If all of the teams are required to join a conference (for real, not half-assed N.Dame style), I could see it happening with the Big Ten and SEC at 16 schools, the Pac 12 at 14, and the Big 12 and ACC at 12 schools each. Or the simpler 14 schools in each conference could also happen with 70 teams and five conferences. If some schools remain as independents the numbers are all different though. We will have to wait and see what happens but I feel that there are between 66 (current big 5 conferences plus ND, Boise, BYU, Louisville, and Cinci.) and 72 (the 66 plus the service academies and 3 oddballs, teams like Syracuse, Hawaii, Fresno St., and Nevada off the top of my head).
-Trying to think of something creative.-