Kevin Carey has written a thoughtful, in-depth blog post on the New America Foundation site discussing his experiences in taking 7.00x.  If you want to understand the best of what MOOCs can be, do not miss this post.
Here’s an except in which Carey highlights some of the cutting-edge tools used for the course:

7.00x took great advantage of available technological tools. So the first problem set opens up a little “Molecule Editor” widget in Java, gives you a question like this, and you manipulate the chemical structure accordingly:
The week two problem set involved 3D protein models that you can rotate around, zooming in and out too see how exactly the various amino acids fit together:
There was also an interactive map of the glycolysis pathway, and a set of problems that involved submitting work done with the Foldit protein-folding simulator:

But definitely read the whole piece.