At this point, divisional alignment has turned into a pissing match between every Pac-12 schools' fans. Fans, not the schools themselves mind you, are jockeying for the best possible outcome for their own school, refusing to make the concessions needed for alignment to work as a whole.
California fans want all the Cal schools to be grouped together. Northwest fans need to play in Southern California every year. Arizona fans have no idea we just went to 12 schools. Colorado wants Southern California as well, since all of their alumni apparently reside there. Utah just doesn't care; they're out of the Mountain West.
With that in mind, I give you the definitive alignment that works for all parties.*
The "everyone else" division plays a round robin because who cares about aligning the conference to maximize BCS chances. It's all about rivalries and recruiting, baby. Ten conference games? No problem, everyone gets to play everyone.
The Palouse, or the WSU, division picks and chooses its opponents based on who they feel like playing every year. Want to skip USC one year? No problem. How about playing two games in Southern California? Gotta hit those fertile recruiting grounds.
At the end of the year, a conference championship game takes place with WSU playing whoever survives the West division with a record above .500. Winner takes all with a Rose Bowl berth on the line.
It's as simple as that. Hire me as an alignment consultant, Larry.
*There is no way to please all the schools with any kind of alignment the Pac-12 comes up with. Everyone needs to make concessions to have a harmonious conference and the most fair outcome to divisional alignment. Don't worry, it's temporary until the Big 12 folds and we move to 16 in a few years.