Tony Romo won't hold out, because Jerry is going to pay him. Jerry may be a polarizing figure, but he is definitely not an idiot. He wants another Lombardi so much it hurts and he knows Romo is his ticket to that. Like any smart businessman, he's simply biding his time and making sure he has the real deal in Romo before making an investment. Trust me, Romo is going to be a very rich man before the season is even over.
And as another poster said, Romo doesn't strike me as the type of selfish guy that would hold out. He knows where he came from. He knows he's an undrafted free agent that is playing out of his head and making jaws drop all around the league, and if you would have told him 4 years ago that he would one day be the starting QB for the Dallas Cowboys and would get offered a contract in the neighborhood of 20-25 million, he would fall over.