Regarding adding Arizona and ASU, what is the motivation behind adding them to the Big 12?
Enrollment-wise, Arizona and ASU are large schools. And Arizona is an AAU school, which would add some academic prestige to the conference. However, according to the college fan base estimate that was published several years ago (and granted, this report is getting dated), Arizona and ASU don't have large sports followings...406,000 and 606,000 respectively. For reference, tOSU has 3,167,000, UT has 2,250,000, OU has 1,201,000, and ISU has 535,000.
And this is part of the Pac-12 problem. Despite having the state with the largest population in their geographic footprint, and several large-enrollment schools outside of California, nobody watches their sports network. College sports doesn't seem to carry the priority in the Pac-12 culture that it does in other conferences.
Arizona and ASU aren't going to bring alot of eyeballs to sweeten the Big-12 TV deal. They are going to add another timezone to the conference. They seem to be average or worse in football the past few seasons, and as such don't draw much national attention. Adding two schools would destroy the true round robin arrangement for most sports in the Big 12.
So apart from the inevitable posts of cute coed pictures, what will those two schools add to the Big 12? Is there some faux sense of stability that comes from having 12 teams? In the current college sports atmosphere, stability comes from the conference revenue distribution. If new members aren't improving the payout, then IMO, they aren't adding any kind of stability to the conference.