I think the SEC, ACC and Big 10 are all quite content with their current situations. They all seem to be making good money.
I don't see Texas leaving what they have for the Pac 12, since they are the biggest fish in a rather small pond and are making tons of money with their own network alnog with the Big 12's TV deals. I even think Oklahoma with their success would want to leave either.
The only school I could see doing anything is Nebraska, which has clearly seen a decline since joining the Big 10, and losing their recruiting base in Texas. But even that is shakey.
The Pac 12 is the P5 that is struggling the most and has fallen behind in the revenue game. And I doubt that any of the other P5 teams would want to leave what they got for the Pac 12 and its relative mess of a network.
I don't have the insider info to make up like MVHer, but I just don't see much more realignment happening.