The PAC 12 unlike some of the other conferences seems to like to keep in state rivals together. You have the Arizonas, Oregons and Washingtons. Look at the SEC/ACC where you have the South Carolina schools split, the Georgia schools are split even Florida doesn't want FSU to come over the SEC. The PAC bucked this trend of keeping state school together when they invited Colorado and Utah. Colorado was a school that institutionally fit in and gave them access to the Denver market. Utah gives them the SLC market? The PAC 12 wasn't that misinformed...their research had to tell them that the money was with BYU. Of course the PAC 12 needed someone to come in right away and knowing what we know about BYU and Sunday play that isn't an easy thing to do with BYU given the short time Larry Scott was given.
So for the PAC to expand and maintain their integrity with the in state rivals later on down the road they would naturally bring in BYU and actually get the SLC market and more. They would also bring in CSU to match back up with Colorado. The issue with this is the unbalanced number of 7 in each division. The PAC would have to do a zipper conference with an example such as this:
Zipper 1- UW, OSU, Stan, UCLA, ARIZONA, BYU, Colo
Zipper 2- WSU, Oregon, Cal, USC, ASU, CSU, Utah
Each team would play everyone in their division every year. The remaining three conference games would consists of one permanent rivalry (Utah vs BYU, USC vs UCLA and etc) and the other two would rotate throughout. Every zipper also has equal access to So Cal for the recruiting as well.
Now the only thing the PAC is missing is access to the Las Vegas market. I think the PAC would rather have a UNLV over CSU. That is the only city out West that is still left hanging without any representation. As far as BYU goes I know the PAC is full of Liberal institutions that don't care for us much. However there has to be a lot of LDS people who have influence in these PAC institutions. BYU has a lot more to offer the PAC 12 as far as money and fan base than Utah and Colorado so we have that going for us.
This is just me thinking out loud.