Just like the title says, you can now purchase apps from the Android Market if you're in South Korea. (There's a larger issue of being able to purchase paid apps in every international market, but that's for another time.) Google's Tim Bray explains:
As of today, Android Market is open for business to application buyers in the Republic of Korea. We hope that this will make the outstanding Android devices now available in that nation even more useful and fun. We welcome the people of Korea, acknowledged everywhere as one of the world's most-wired societies, to the world of Android.
Good to see things continue to grow. [Android Developers Blog]