Hello!
I think, there should be more user created content on koreanclass101. You could ask the users to write a homework an a special topic every week and let them submit it to a board - and then probably also make them correct each other. You could ask the users to submit an audio file as a response to a podcast. They could also upload videos where they speak in korean. I think, it would be fun to interact this way and meanwhile learn korean by using it.
Stefan