It primarily requires ISDN lines at least, to carry the bandwidth. Many of the concepts discussed sounded very similar to our current ITV network. The main issue I saw was the setup and support required for configuring and maintaining this hardware. This would have to be a lab solution. It did have many benefits but the costs were unknown.
Most students learn by doing.
Low completion statistics. Combine CBT with video conferencing. Generally keep internet class sizes down to around 20, and video conferencing class sizes down to 10.