I really have to hand it to Blizzard, they know the long haul and they are in for it.
Single-player games are not inhabited by raging sociopaths, loot whores, and idiots. Or if they are I haven't played with them yet. Clearly single-players games have better communities, as seen here in this graph, which you should note is entirely blank.
Could WoW tap into this? Yes, and it's a work in progress. You see, there's actually an inflection point in the graph of the community; there it becomes so degraded that it actually becomes better. We saw this strategy executed in EverQuest in which a whole lot of anti-social nerds managed to work together in huge groups and even manage to think of it as a fun experience, as opposed to their usual reaction to other people: running in screaming terror.
As you can see, the graph shows that losers who play EQ will normally form a really awful community, getting worse as there are more, until eventually there is a critical mass of nerds in which social reactions can begin, resulting in a rapid increase in community.
Blizzard has a long tradition of taking what everyone else does well and doing it better. So they've added tools and ideas to utterly destroy all sense of being a multi-player game, eventually resulting in peace and harmony among the community. Sure, in the short term we might not like the extreme alienation caused by facerolling randoms with random people who we will never see again. But in the long term we'll stop caring and just think of them as NPCs. Some people already do. Those are the previously mentioned sociopaths. They're ahead of the game, literally.
But Blizzard doesn't go halfway. They go all the way, and then halfway further. Never try to go on a trip with them in the direction of water, desert, mountains, or really just about any vertical and/or horizontal object, because they will smash right into it at very high speed. Which is of course their plan. So they've added such incredible gear inflation that simply having good gear isn't good enough, now you need [arbitrary number], plus 500. This combined with easily trivialized mechanics to make instances so easy that all you ever need to ask anyone is is why they are so retarded to spec fury with that hit rating. Or whatever it is that a fury warrior should have.
So as you can see here, the changes are quickly destroying the WoW community. But at the point where it becomes a single-player game, it actually gets better.
So do your part to form a better community: Solo as much as possible and avoid thinking of other players as people but instead as poorly-written AI. If you insist on dynamic interaction or the 'players' try to talk to you, be rude, offensive, degrading, inflammatory. They might think you're a total asshole, but in reality you're just saving the community from itself. It's how we won Vietnam: by destroying the village to save the village, since as we all know "better dead than Red" is best applied to other people without their consent, since they might dissent.
Thank you, America. Europe, uh... bon jor we we?