North and South Korea trade artillery fire. The Seeds of War?

North and South Korea are at the brink of war with both sides shelling each other over a disputed island.  The latest:

New York Times:

"Crisis Status" in South Korea

Wall St. Journal:
US and World Stocks tumble

Fox News:

Attack makes North Korea a Foreign Policy Priority

Korean Herald:
South Korea may strike North Korean missile base

Korea Times:
2 Korean Marines died - 19 civilians injured in attacks

Video:

North Korea shells South Korean Island