I think the world is better off with the terrorist Osama bin Laden dead. However I was a little shocked by the reaction to the Archbishop of Canterbury's words about feeling uneasy about the "taking out" of bin Laden.
Christians have a duty of bringing the voice of Christ into the world which normally doesn't want to hear it. It simply doesn't understand the Christian way of meeting injustice with mercy, violence with turning the other cheek. Some Christians themselves ignore Christ's words about his Kingdom not being of this world. Evil is never overcome by evil, even a little evil.