He should be scared:
According to senior military officials, al Sadr left Baghdad two to three weeks ago and fled to Tehran, Iran, where he has family.
... Sources believe al Sadr is worried about an increase of 20,000 U.S. troops in the Iraqi capital. One official told ABC News' Martha Raddatz, "He is scared he will get a JDAM [bomb] dropped on his house."
Sources say some of the Mahdi army leadership went with al Sadr.
Though he is gone for now, many believe al Sadr is not gone for good. In Tehran he is trying to keep the Mahdi militia together.
Jack Cafferty wondered on CNN how Sadr could have slipped out of Baghdad with so many American soldiers around as part of the surge - He lives in Najaf, not Baghdad (HotAir)