Hell will visit them in a few days !
Yes, the Marines are p*ssed off as are many other people but the civilians that give orders are now fighting a PC war and will keep the marines and other troops on a short leash.
We'll hear about a lot of investigating and interrogating but I seriously doubt that we'll see retaliation of any significance, if any at all. After all, we're in a nation building mode now and don't want to upset the transition of power, doncha know ;-)
Paul Bremer is pi$$ed about this too. Things are going to happen.