I don't know too much about Korean politics, but it appears as though the GNP (conservatives) got rocked in the latest elections, which was pretty unexpected. This is bad news for those who think that the current appeasement policy endorsed by the Roh administration has been ineffective. I also think it's bad news for U.S.-Korea relations because the GNP has generally been the pro-U.S. party, and some pundits think a major reason why Roh was elected was the result of Anti-American sentiments during the last Presidential elections.
As far as I can tell, the GNP is still favored to win the Presidency, but these things can change quickly depending on which underdogs decide to form a coalition at the last second, accidents involving U.S. tanks, etc. But even if the GNP controls the Blue House, its hands may be tied if the legislature is controlled by opposition forces, much like the situation that Roh faced.
Of particular interest was the fact that the GNP was destroyed in Daejeon (which I guess is like the Ohio of Korea in terms of politics), which might indicate how swing voters are leaning. The guy who won, Sim, also compared himself to Alexander the Great in a bizarre reference, but that's off the topic.