When I played WoW, I was part of a group that was more of a social thing than a battle group. We'd share resources, help with quests if someone needed it, and generally we had a good time.
They've become so ingrained into our daily lives that I don't think they'll go away any time soon, unless some new ground-breaking tech makes an appearance.
Thinking about how things were getting off to a bad start this morning, and then I remembered Friday the 13th falls on a Wednesday this month so that kind of explains it.