A fair assessment of my abilities:
Speaking - I have a very thorough vocabulary, but at times, I phrase things awkwardly. I have also been told that I say certain things like a baby (i.e. "You am nice" or "I have wented there" - exaggerating, but you get the point) because I have never been corrected on my Korean - I just gradually pick up things from TV, the news, and other Koreans.
Listening - I would say I'm on par with native Koreans. I have yet to hear any Korean that has stumped me. Of course, I would not be able to take a college biology or calculus course in Korean and actually learn anything. Korean literature I could probably manage. Maybe even history. But that's about it.
Reading - I comprehend everything without a problem, but it takes me a long time to get through the hangul, and I also can't just read it - I have to vocalize it at least in my head and hear how it sounds in order to understand it.
Writing - umm...no. I know hangul...I can guess at spellings based on their pronunciation. But considering that I have a regional dialect, it's not usually right

I would say I'm too advanced to go through any course designed for someone without a native background in the language. I know for languages like Spanish, there are specific classes available for people like me, who can speak and comprehend well but never learned the grammar, nuances, etc. Is there such an option for me as well? I was planning to just read through newspapers for half an hour every day this summer, but when I discovered this forum, I wanted to hear your advice as well..
Thanks for getting through this long post, and thanks for your reply in advance!