Sequel To Follow The lines Of “The Empire Strikes Back The 2009 reboot of “ Star Trek ” was a shining moment for fans of sci-fi and spectacle films and the sequel, due in 2012, may well follow the box-office trajectory of the Christopher Nolan Gotham City films — “Batman Begins” earned the credibility with fans old and new and then “The Dark Knight” delivered the billion-dollar payoff. “ Star Trek ” writers Alex Kurtzman and Roberto Orci , the tandem that also penned “ Transformers ” and next summer’s “ Cowboys & Aliens ” and also created the Fox sci-fi series “ Fringe ,” are back to script the sequel. The LATimes caught up with the screenwriters, who talked about the challenges ahead and also shared a playful aspiration — an on-screen showdown between Captain Kirk and Darth Vader . LT: It’s early days on the “Star Trek” sequel, but is there anything you can tell us about the story direction, tone or even the types of challenges you’re anticipating with this next-step projec