It's so rare that an evil butcher actually gets his just desserts - usually they get away with it. It seems that the magnitude of the crimes committed are inversely proportional to the chances of receiving justice. If you kill one person there is a fair chance of, at least, spending a considerable amount of time in prison, or of being executed (depends on where in the world you commit the crime). Kill thousands, or 'better' yet, millions and there's a pretty good chance of dying of natural causes - in your own bed (or possibly hospital?) if you're Pinochet or a comfortable cell in the Hague if you're Milosevic.

Unfortunately, I suspect that Saddam's death has very little to do with justice (although I believe that he richly deserved to die). I think that he was swiftly despatched because he knew too much and because he was a puppet of external forces who had outlived his usefulness.