This comes from Politico.com:
President Barack Obama said Thursday that he did not foresee an immediate withdrawal of U.S. troops from Afghanistan in July 2011, the date he has set for the start of the drawdown of U.S. forces. "We didn’t say we’d be switching off the lights and closing the door behind us. We said we’d begin a transition phase that would allow the Afghan government to take more and more responsibility," he said at the White House, a day after naming Gen. David Petraeus his new Afghan commander. He also said he didn’t foresee any other high-level departures from his Afghanistan policy team.
An immediate withdrawal? No, but a withdrawal at that time was promised. You can interpret the president's decision as someone who doesn't understand the military situation and therefore made a rash judgment when he announced that day. Or you could interpret it as a leader who recognizes that changing circumstances require that previous guarantees need to be reconsidered.