Some thoughts:
1. BYU is a non-starter for 2 reasons: not a research university and their refusal to play on Sundays (no problem for football, but basketball and Olympic sports need Sunday games).
2. The discussion about academics misses the point. It's not about acceptance rates or SAT scores, it is about the definition of a research university: does the university invest a lot in research, and does it grant a wide range of Ph.D.'s? ASU, for instance is a lousy undergraduate school, but has a number of well-established Ph.D. programs as well as recognized scholars. Currently, all Pac12 schools are research universities. By most definitions, SDSU, Fresno, BYU, Boise, etc. are not. Texas, OU, OSU, Baylor are.
3. One theory is that eventually we will go to 4 16-team "super conferences." If that happens, it is likely that the B12 will be put to rest, and the 4 survivors will be the B10, P12, ACC, and SEC. The B10 and P12 will then presumably cannibalize the old B12, with the remainder going to the ACC.