You could talk about gaming on any of the social communities (in fact, there are discussions related to gaming on them now).
The exercise tracker has a place for tracking time spent playing Wii.
I don't know about this. This is coming from a person who at first felt the general social community was getting too far from the original medical focus of the website. Eventually I got used to it, but as a result notice I have gradually drifted my focus away from what it was when I first joined here.
If there were games or game focused communities, I feel that would be even more straining on what this website was focused on. At least what it was focused on orginally. If we go that way, what would make this community that much different than facebook, myspace, or livejournal?
As Peekawho suggested, if you'd like to talk about gaming, the most appropriate community would be the MedHelp Social Community.