Alarmingly, there may be no sector of society where technology has had less impact.
I think this is probably true and also would add higher education classrooms to the list. I've blogged about this before.
K12 education persists in operating on the premise that to have school, you must physically co-locate teachers, students and curriculum materials. Teachers and students are assigned to stand-alone, self-contained school buildings that house paltry collections of mostly outdated curriculum materials. With rare exceptions, digital technologies and interactive communications are still largely peripheral to the primary activities of the typical school day.
I think as online education, rich educational gaming environments, and other options grow and flourish, many folks' deeply-cherished beliefs about what school must look like are going to be put to the test. There always will be a place for face-to-face schooling, but it will be interesting to see what the landscape looks like twenty years from now.