Duke Nukem 3D was a very popular game in 1996 - and was revolutionary at the time for it's charachter and interactivity (which still rivals modern games), I have been a part of the fan base ever since I first discovered the first three games (In Makro of all places) and made my dad buy them for me (I was only 6 years old)
Here is some footage of Duke Nukem Forever;
http://www.youtube.com/watch?v=XoRJlEbNVAs - I did not upload this.
It is coming to XBOX 360 and PC - Might be on PS3 and Wii also, but I don't know yet.
Over the years the game turned into a joke, many forgot or just made fun of it saying it will never come out, finally it has, I personally am overjoyed, but obviously having never heard of it you won't be.
There will be a trailer coming later at 2K Games anyway.
Here's a random news article;
http://kotaku.com/5628894/its-official-duke-nukem-forever-coming-from-gearbox-software