If you purchase Borderlands: Game of the Year edition you get access to the "Duke Nukem Forever: First Access Club". Which will allow players to play the demo before anybody else. And you should only get access via purchasing the Borderlands: GOTY edition. But it appears if you own Borderlands on Steam then you also get a key!
To find your key simply load up Steam. Go to your library and find Borderlands on your list. Right click on it and select "View Game CD Key" and a little window should pop up with a list of Borderlands CD Keys. At the bottom should be your Duke Nukem Forever: First Access Club key.
Highlight the key, press "Copy key to clipboard" and enter it into the site below along with your email address and they will let us know when the demo is available to us :)http://www.dukenukem.com/access/
There's also some free wallpapers once you've input your key. :)
Can't believe the game is finally going to be released.
Let's hope it's good! :D