According to Superherohype 20th Century Fox has announced that it will debut its trailer for X-Men 3 on December 14th at showings of Peter Jackson's King Kong.  Since King Kong is a Universal film, which gives Universal the only guaranteed spot on the trailer reel, there is no certainty that theater owners will play the X-3 trailer; however, given the prominence of the X-Men franchise and the fact that most multiplex owners and managers will be showing X-3 when it debuts next Memorial Day weekend, it is highly likely that most theaters will run the trailer for the new X-Men film.  Certainly there would appear to be a strong crossover from the King Kong audience to the potential X-Men audience that theater owners would find hard to ignore.