The Big 10 TV Network has helped that conference keep up with the SEC. They are getting business nationwide with it (including on the Comcast sports package in Portland). Paid by subscriber. They're making so much money that, now, Notre Dame has declared that they're "rethinking independence." The Big 10 has a lot of suitors for expansion.
The Pac-10 must keep up with that in order to compete. Problem- the West isn't as historically grounded, not as many fans of the college teams as there are the pro teams (noting that most Pac-10 schools are in pro markets, or certainly draw eyes from the large markets that have pro teams). That's why, when the possible "Pac-10 Network" was envisioned, it quickly became a "possible partnership with another conference" network. The ACC and Big 12 are the mentioned partners.
Somewhere along the line, people are going to discover...
...this kind of network will get more views selling Texas football, or maybe Carolina basketball, than anything Pac-10. Texas can hold back, but the numbers there will raise eyebrows here...
...culture means squat when you're relatively impoverished.
You may be right to question Texas coming to the Pac-10. They'll insist on being in the "Pac-10 South," forcing Cal and Stanford to the North, which Stanford certainly will veto. Since it needs 10 Pac-10 votes...
...that means USC would have to at least threaten to leave the conference in order to shoot for the bigger bucks.
About the WAC... geography matters to a conference that isn't getting more than $400,000 per school from TV to play on nights nobody but ESPN would ask you to play on. When ABC and 7 or 8 digits are involved, it matters a lot less.
Summary- It's possible nothing will happen for now... and that's what will cause problems down the line.
UC Davis, Sac State to share new $450M football stadium in West Sacramento