Although online school is a very vast subject, with many ways of approach, my take on it would be short and simple.
While most of the students would initially love this way of learning, after a while, things like not having to dress up every day, lacking an exact schedule, or not being able to meet your good friends for a gossip between classes, would slowly become very annoying. We all suddenly realize that besides learning, social interaction is a very important thing.
Overall, online school is fine, as long as it is an option and not the only single way of learning. Taking a course online is great and can be fun, but completely switching to online school is not a good thing at all.