The following video is a fine example of what technology in education is NOT about (a video report from The Chronicle of Higher Education). Robot teachers have been a feature of sci-fi movies and literature for decades and although these Korean cyberteachers are rather charming and have no doubt excellent technical merits they have very little to do with teaching. At best they are extremely expensive self study tools based on the assumption that teaching is the transfer of facts.
The role of the teacher is indeed changing. Instead of deciding what to learn, today's teacher concentrates more on helping students discover how to learn as a vital life skill. Learning is a social activity and it's very difficult to learn effectively without getting feedback and encouragement. The teacher's role as a mentor and facilitator is a supremely human one and the children in the film seem soundly skeptical to the robot's lame and disengaged encouragement.
If there is a lack of native English teachers in Korean schools why not get schools to link up with teachers via Skype and collaborate with English speaking kids through social media? Technology provides us with great tools to help us with uniquely human processes.