Well, there's got to be someone out there who isn't planning on going through Bioshock this weekend. I'm among you, actually. I'm instead going to be spending my time playing Guild Wars, as they're having a preview weekend for their forthcoming Eye of The North Expansion.
While the game proper goes live on August 31st, they're giving people who've pre-ordered the game 72 hours of running around and generally trying to power their way through as much content as possible from the 24th to the 26th. And, most importantly, all progress and achievements will be absolutely valid when the game goes properly on, so you're not wasting your time. Clearly, this is an attempt to get as many pre-orders as possible, but that's just a fine mutually reciprocal relationship. Arenanet get lovely, lovely money. You get to wander around the newbie zones on August 31st and wave your magical equipment at them braggingly.
That said, for Eye of the North, it's worth nothing that the newbies won't be newbies. This is the first of the Guild Wars games that is a genuine expansion - in that you need a level 20 character to access it. If you don't... well, you should. Guild Wars is excellent, and if you haven't already, I'd recommend you start at Nightfall. But if you don't, there's always that Defcon weekend. Or some other game.
Oh, we can't escape it.