LOL.
With all due respect to the fine, unfortunate employees of 3D Realms, Duke Nukem has just become immortalized as the poster boy for vapourware, oft-delays, mismanagement and probably a half dozen other industry ills.
I doubt Duke Nukem Forever would have even sold well at this point. The franchise is so stale and outdated now it'd be more of a curiousity than a FPS contender.
I don't care if the game ever comes out but I'd love to see a documentary on Duke Nukem and what went wrong for sooooo long.