Tom Goldman said:
Gabe Newell: entertainment is inherently increased in value by having it be social, by letting you play with your friends and recognizing that you're connected with other people.
No.
I'm sorry, but this is completely wrong. Ironic that this should come up on a site called The Escapist, really; surely the point of escapism is that you want to, well, escape? To leave behind the real world and engage in a fictional one, without any of the ties that remind you of your day-to-day life? Adding a social component to a game when you're trying to lose yourself in that game's world is just going to remind you that you're playing a game, and drag you back to grim, depressing reality.
Would a novel be greatly improved by having someone sit over your shoulder and talk while you read it? No. Would film be improved by natter? Imagine how annoyed you'd get if you were trying to watch Inception in the cinema, and people insisted on talking throughout it. Single player games, likewise, will not be improved by adding a "social" component. The entire point of a single player game is that you don't want to be social.