Ibn has pointed us in the direction of The Daedalus Project, a non-commercial project that gathers information relating to games and gamers, and has published some interesting information in the past. This except is taken from their most recent issue:
In fact, as the following stories demonstrate, a virtual wedding is a combination of social entertainment, extensive role-playing and sometimes political intrigue. Instead of thinking of a virtual wedding as the corrupt bastard child of a real world contractual agreement, the virtual wedding should be considered as an elaborate form of collaborative digital story-telling - a ritual of its own right that fulfills a completely different purpose.
Their current issue looks at topics such as guilds, ingame romance, online friendships and addiction, amongst others. They're also looking for current MMORPG players to take part in a survey, aimed at gathering information for their future reports. If you're interested in helping out, the survey can be found here.
