I really enjoyed this article, thanks for posting the link. I knew David Kushner was working on some stuff for D&D but did not know this was one of them.
Reading it really makes me sad that Gary is gone. I would have loved to have gone to his event to have the chance to possibly play in one of his games.
I also would have liked him to see the 4e rules. I am not sure if he would have approved or not. My hope would have been that he liked the new rules, with less emphasis on perfect simulation, instead a focus on rules designed to be more intuitive. It sounds like he liked his games to be less rules intensive and more focused on the creative side of roleplaying.