OU wanted to bolt for PAC12 a lot more than UT, but current TV deal kept them there. I have a feeling they'd happily join B10, SEC, or PAC12 if invited. This will be magnified a million times if they have a great season and don't get into the playoffs.
UT on the other hand has a LOT to lose by leaving. They are the flagship team and have a lot of emphasis riding on the LHN. However, seeing A&M ride like they are has to make them very envious. I don't see them going to the SEC, they'd get swallowed up, but a B10 or P12 would work if the B12 disintegrates.