Although it is certainly debatable if racism can simply be fixed via legislation (how's that working out for South Africa? It's complicated...), I think that bringing the issue into the open within Korean society might start discussion and cause people to start reconsidering their attitudes.
I personally cannot recount many instances of racial discrimination towards myself while I have been in Korea. This is probably due to me being a white male from the US.
In some cases, I have experienced the "foreigner seat of death", where no one will sit next to me on the train until there are no other existing options.
I have seen this happen as well with people of Southeast Asian decent.
However, such stories are trivial compared to what the person who wrote the article above had to deal with. His is not the first such story I have heard along those lines; the author of this blog - http://metropolitician.blogs.com/ - has had his share as well.
I am not holding my breath that these attitudes in Korea will change overnight; I have hope that the younger generation handles it better; they mostly seem more tolerant and worldly to me.
In a larger context, such stories like this have been and will probably continue be repeated across the world in nations that were traditionally of limited ethnicity soon have to deal with an influx of immigrants.
The US, Canada, and perhaps Australia and the UK could offer some examples for how to better integrate immigrants, though countries newly in this situation will have to be willing to learn.