I wouldn't hold my breath for any PAC 12 team joining the Big 12 especially USC. Also, Texas is not joining the B1G for money. They make plenty of that right where they are and are able to pull all the strings in their current conference. They're NOT giving that up for anyone.
We'll see what the near future brings to the Big 12 in regards to expansion. Their TV deal is up relatively soon.
FYI, ASU is one of Scott's biggest supporters.