With the death of 3d Realms a wealth of Duke Nukem Forever information has been leaked to the world wide web. There’s been screenshots and a demo reel showing some real gameplay and now there’s design documents. Specifically some Level Design documentation and since I’m always interested in the way other people work and plan, this is a good luck.
On IGN you can find a document covering three levels of the game and there’s also a reveal of the plot overview document. I’m not entirely sure this is genuine but since I haven’t yet had a good look it’s hard to say. It certainly looks that way to the IGN folks.
Thanks to Kim for the tip and the links.