Here's the progress of educational tools:

  - Lectures  
  - Textbooks  
  - Lecture videos   
  - Interactive tutorials

It would be great to move beyond videos and build courses around 'explorable explanations' and other interactive tutorials.

(I'm looking for such tutorials on my site https://www.learneroo.com/ . Email me at ak[at]learneroo.com if you're interested in collaborating)