As the title suggests, Computerandvideogames.com have interviewed Ken Levine, Creative Director of Irrational Games (at least I think that's his new job title. Head honcho, anyway)

Twist, from our forums, points this out as being an interesting, if not a little suprising, quote from the article:

CVG: What's Bioshock's story then?

Ken Levine: I haven't finished the story to Bioshock yet - I know the thrust of it, but I'm getting a hard time from our producers because I haven't written all the dialogue yet. Ask everyone who's ever worked with me, they hate me because I take forever with that stuff. I let the game tell me, as it develops, what to do. Some things are accidents - you see something in the game world and can create a hook from that.