I'm in the don't care category, whether he's dead or not has little bearing on my life, but since I believe the world is over populated I'm glad there's one less person wasting resources.
From a moral standpoint, he's obviously not the only person to do what he did and the bulk of those like him will probably go unpunished but since there is no shining beacon of truth and righteousness in the world that can pass judgement on all the tyrannical despots we'll just have to make due with the US government.
And Carnage the US didn't execute him, a bunch of Iraqi's with funny necklaces decided to execute him. We just went in and took the guns away from most of the people who would have killed the necklace wearing people before they could pass judgement on him.