As someone who's both taken online college classes and who currently teaches at a large four-year university, I think it's a stretch to claim that computers will completely replace traditional face-to-face classroom instruction. Online courses run a very wide gamut from little more than a glorified correspondence course to truly top-notch classes with educational quality to rival the best bricks and mortar.
However, online classes have a much higher attrition rate than traditional classes. It takes a heightened level of motivation to keep going, simply because you don't have the physical presence of classmates and a professor who will hold you to account as she gazes in your eyes. When I did (an admittedly unscientific) survey of my students, I found that a high percentage of them had taken online classes but preferred face to face because it was easier. They told me that when you're on your own, you have to figure everything out yourself. Sure, you can email your teacher a question, but you've got to wait to get a response and then maybe it's not clear and you have to ask again, etc. Conversely, most questions can be explained/handled in person in a fraction of the time.
As well, in my classes, I spend a lot of time working with students step by step as they brainstorm, draft, revise and so on. We do mini-lessons on the fly as they need them--I respond in real "real time" based on what they're currently doing and need. That said, I think MOOCs and similar venues definitely have their place, especially for higher level college courses and non-traditional students who are typically more focused and motivated. There's no question the education landscape is changing.