While North Korean leader Kim Jong Il is a madman, and while North Korea was the first to kill anyone in today's skirmish, it was actually the South Koreans who fired first.
As AP notes:
The skirmish began when Pyongyang [i.e. North Korea] warned the South to halt military drills in the area, according to South Korean officials. When Seoul [i.e. South Korea] refused and began firing artillery into disputed waters, albeit away from the North Korean shore, the North retaliated by bombarding the small island of Yeonpyeong, which houses South Korean military installations....And see this.
In addition, the two South Koreans killed were marines, not civilians, stationed in a military town.
Obviously, firing artillery into the water and actually killing people are very different, and I am in no way defending North Korea or its crazy leader. I am simply trying to point out that the headlines can't be taken in a vacuum.