His seat is still warm, but names are already circulating for who will take over as CENTCOM Commander when Petraeus heads to Afghanistan.
The front runner for now is Lt. Gen. John Allen, who has been deputy commander of CENTCOM for the past two years. He's a Marine and was recently on a short list to be the next Commandant of the Marine Corps, but he was passed over, because Pentagon leadership thought he would be better as a combatant commander. Now he has that chance.
At a minimum, he'll be the Acting CENTCOM Commander after Petraeus is confirmed by Capitol Hill.