I'm gonna play it at my friend's house once he gets it.
Meanwhile, I've been sampling L4D single-player. It's fleshed out enough that it feels like a real game, and not just multiplayer with bots, though it's still a bit...empty feeling to me. Not to mention the end-chapter assaults are hard as crap with the miserable AI backing you up. Hunters I can deal with, but Smokers constantly pulling me (and they seem to focus more on me) and Boomers spawning left and right, as well as Tanks popping up with unholy frequency (which is to say, more than once a chapter), are more of a challenge when I can't tell one of my dudes to stop what they're doing for a sec because my freaking skull's getting chomped on by roughly 20 zombies while a Smoker holds me up like a pinata. Really, Valve should've put in a quicksave in single player. It's common courtesy.
However, I did manage to rack up a few achievements to impress the ladies once I venture out into the online abyss.