The WAC already tried this, and it failed miserably. And that was a very similar conference- a hodge podge of West Coast teams and Southwest Conference leftovers. The WAC ended up breaking up into the Mountain West and WAC.
The funny thing is, when this PAC-16 or whatever breaks up, it will essentially be a reformed Southwest Conference with the old Big 12 teams and the two teams in Arizona and probably Utah should things go down like I think they will, and the old PAC-8 teams.
And yeah, the WAC didn't have any big name schools like USC, Texas, or Oklahoma, but I think there will be some very similar issues that will arise.
I just can't see USC and Texas getting along in this thing. Maybe they will, but SC, while smaller, has a pretty good bit of money and clout in their own right.