The Sense of Community: Multiplayer Games

Video games seem to be one of the stronger emerging forms of media these days and that in turn has caused a sort of cultural and social shift for some. Consider Multiplayer Online Battle Arenas (MOBAS) which have friend and party functions built into their games. MMOs as well have an in-built social function with things like public chatting in Runescape. It would also seem that these social aspects in video games would transcend the in-game functions and disperse into various mutual fandoms. Online communities and more for all these games are growing and becoming more prominent along with the medium. How do you think this has come to be? What does this mean for the culture surrounding video games compared to how it was before?