With the Games MOOC, the makeup can vary alot. We will have a number of people who have never logged into a virtual world or a video game. We do seems to always have a decent number of educators who are Second Life-ers or were. For the June part of the MOOC, the focus will be on MMORPGs. In July for Part II, we'll be in every virtual world for a whirlwind tour.
As far as looking for collaborators, that's wide open. It could be a F2F meetup to talk about the weekly topic or a virtual meetup. Group formation in virtual worlds sounds great. Since this is a connectivist MOOC, we like to encourage it rather than mandate it.