I'm not Nostradamus but I think English is improving and in the future many more people will be speaking English with greater ease than when the native English speakers first came here.
Younger Korean English teachers, fresh from teachers college are adding new ideas to the curriculum. They are using computers in the classroom, getting ideas off the Internet, and very often they have had training in the United States or Canada so they can communicate easily with native speakers.
Hopefully this school will continue to employ native speakers. I don't know if there will come a time when the public school system has no more use for the native speaker.