Great topic, Russ! We spend so much time talking about games, yet we often don't stop to think what makes one game better than another or how one goes about designing a game that people will enjoy. Perhaps most importantly, we rely so much on the tropes and genres that we are used to that we forget that games are about more than just shooting, racing, and sliding puzzle pieces. There are so many ways to build that conflict beyond the models we are used to and each holds an exciting opportunity for new and interesting games.
By the way, may I suggest asking Raph Koster to contribute an article for this series? I'm a huge fan of his book "A Theory Of Fun for Game Design" and I bet he would me more than happy to speak to such an interested audience.