The Sporting News reports the Astros sale is being held up by Bud Selig because he wants Jim Crane to agree to move the team to the American League:

Included in this series of dominos that must fall is Jim Crane, the potential owner of the Astros, who has opposed the idea of the team switching leagues.

I though Bud wanted Jim to buy the extended warranty and the undercoating. Also good to see the commissioner is not above blackmail.