UPDATE: Here is the official statement from the conference:
In light of the widespread speculation about potential scenarios for Conference re-alignment, the Pac-12 Presidents and Chancellors have affirmed their decision to remain a 12-team conference. Pac-12 Commissioner Larry Scott said, "after careful review we have determined that it is in the best interests of our member institutions, student-athletes and fans to remain a 12-team conference. While we have great respect for all of the institutions that have contacted us, and certain expansion proposals were financially attractive, we have a strong conference structure and culture of equality that we are committed to preserve. With new landmark TV agreements and plans to launch our innovative television networks, we are going to focus solely on these great assets, our strong heritage and the bright future in front of us.
Jon Wilner just tweeted a bombshell: The Pac-12 will NOT be expanding.
"After careful review we have determined it's in the best interests of our member institutions .. to remain a 12-team conference."
This is huge, considering just earlier today it looked like the conference was on the verge of adding Oklahoma and Oklahoma State.