He was a really nice guy, with interesting things to say, experience in the games industry and currently doing a PhD on Game Design (which apparently counts as Fine Arts). He also seems to have at least 2 if not 3 blogs so I wouldn't be surprised if he was interested in swapping a few ideas and brain-storming a bit.

I've not heard of Greg Costikyan and Ethan doesn't cite him in his abstract, though that doesn't necessarily mean he's unaware of him. The abstract itself should go on the web fairly soon - its a matter of me and the convention organisers co-ordinating ourselves...