GeoPolitics is fun, and please continue keeping it "non-offensive".
In actual fact, China is not all that happy with North Korea, and recent intelligence http://www.stratfor.com/anolysis/20101129_china%E2%80%99s_response_yeonpyeong_barrage has revealed that they may be warming to the idea of a unified Korea (wouldn't that be Awesome!).
It is very likely that, as many times in the past, the North is ratcheting up the pressure so that it can extract concessions from the US in bi-lateral negotiations (and Fuel Oil is _always_ on this list). This worked with Clinton, worked less with Bush, and the North also knows that Hillary (remembering her Husbands experience all too well) is not at all willing to play that game anymore. She has been Very bombastic in speeches over the last two years that she wont play that game. Here we are, at the onset of Winter and the economy in the North is in even Worse shape than before. The North knows this, and I think they are trying to ratchet-up the pressure to such a level that they can overcome our objects and extract more concessions. I think we are seeing a combination of need for concessions by the North combined with a leadership transition is what is Really happening here - and its very likely that China is already pressuring them on the issue (though they would never openly admit that).
What made this different is that civilians were killed, and the North can't deny the attack this time. That has provoked such an outrage among the South Koreans that president Bak has _no_ choice but to respond with serious military threats. We in the US also had no option, we have to show unfettering support for our ally in this matter and stand shoulder to shoulder with our S. Korean brothers and sisters, and thats why we sailed the George Washington carrier group into the Yellow Sea. The sad part is I don't think the North intended to kill Anyone, as other reports from Stratfor indicate that the pattern of artillery fire was more consistent with Old maps of the island. It is thus likely the North was trying to bomb what it thought was a military installation, but has in fact crowded with hundreds of homes now.

I think this was the real tragedy of the event.
Its tense, but I don't think the North is ready for war. In any respect, I really don't think anyone should run around town stuffing garbage bags with Cigarettes (this made me laugh too

). However should it come to war between the North and the South, the US will have absolutely No other response but to goto war to support the South - we still have 28,000 troops there. We really don't need more war in the world right now!
Miax