It is surely good news that Grand Ayatollah Sistani, the top Shia authority in Iraq, is down with U.S. efforts in Najaf and elsewhere. But like everything else in play in the country, the truly important stuff starts once Saddam is gone.
Such as, how will Sistani react if the U.S. starts bringing in Iraqi Sunni exiles to run the new government? Would Sistani even accept another secular state? He has wisely made himself valuable to the U.S. now. That doesn't mean Sistani's interests will always dovetail with Washington's.