Not a rumor, just logic.
Texas on its own is going to have trouble scheduling 12 games. They're going to need to band together with some independents and also have and ESPN throwing money around to lure opponents. I personally don't see how that's going to work out well from them.
I think they overestimate their importance to college football.
And if they stay independent, they're hurting themselves badly in any national championship race. SEC, PAC10, Big10 teams all get to play a conference championship game, which is an extra game against a quality opponent. We've seen many times that this extra game is BCS poll leverage against other teams who don't get to play a conference championship game. Texas won't have that game anymore.
I'm not a Texas hater. But I'd love to see them trip & fall, and put themselves 10-15 years behind because of their arrogance and what they've done to the Big 12.