I recently opined the general dearth in the use of the Web as a vehicle for explaining/detailing complex phenomena that involve movement, 3-D views and so on. Stuff that no amount of colour plates or line art in paper-illustrations can ever match.
Interactive software of the GUI persuasion is a good example of this. No amount of screen shots can come close to actually looking over someones shoulder and watching them do something.
So, I applaud initiatives like showmedo and wish them every success. I'm sure the Python training videos will be a big hit.