For a week anyway.
"If you're going to buy the game this week, I highly recommend you stay away from any forums that might have spoilers until you play the game through. Our goal in making the game was to thrill and, often, surprise you.
Please don't ruin other people's experience by revealing secrets in unmarked threads, and if you want to enjoy the game to its fullest, stay away from any threads that might ruin the fun for you. With a game like BioShock, it will really make a difference."
I'll echo his words. I'm a bit over half-way Bioshock at the moment, and there's certain reveals which you really want to play out as they've crafted them. The one which I've just hit is as powerful as any plot-beat I've experience in gaming, I think. And that's all you'll get out of me from now.
Oh yeah - if you're a XBox gamer, be careful with even reading friends profiles. Plot elements turn up in some of the achievements.
Oh - and while on the topic: THERE IS NO TYLER DURDEN.