RE: SADR. To say a bit more on Sadr's freeze of the Mahdi Army. My understanding, based on a briefing today, is that no one really knows what this means, but that there are a few candidates. The most interesting is that Sadr has lost control of some of his militias, which helps explain why they're killing 50+ people in tactically moronic clashes in Karbala. He's shutting them down in part to regain control over them.
Another argument is that Sadr's attempts to move towards a political role are growing ever more sophisticated, and he's concluded that being part of the current sectarian violence can only hurt him. In six months, when the surge is supposed to end, he'll reactivate the Mahdi Army, step into the breach, and clamber to the top of the political heap.
But I think the honest truth is that no one really knows what he's doing, nor what it means. Conservatives will claim it's evidence of a working surge, but that's bluster: For now, we have no idea what, if anything, it's evidence of, nor what Sadr's endgame in the political reconciliation business is.