Duke Nukem Forever will be getting its second bit of DLC on December 13 which will add a new campaign, weapons, enemies, multiplayer maps and Achievements/Trophies. ‘The Doctor Who Cloned Me’ will cost $9.99 on PC and PS3 or 900 MS Points on Xbox 360. From Official Site: Duke Nukem Forever’s new Add-On Content, Duke Nukem: The Doctor Who Cloned…