For over 70 years, the criminals of Gotham City -- widely regarded as a superstitious and cowardly lot -- have been kept in check by the vigilante known as Batman. But that's about to come to a stop, as the Caped Crusader has officially announced his retirement.At least, this version of Batman: Confirming long-standing rumors, Christian Bale revealed in an interview with The Philippine Daily Enquirer that " The Dark Knight Rises " will be the final Batman movie for both himself and director Christopher Nolan Even the Joker is shedding a tear.Not that the announcement is unexpected; after all, with "the Dark Knight Rises," which just finished shooting for a July 20, 2012 release, Bale and Nolan will have made their third Batman film in the past seven years. Still, considering how successful the franchise has been -- 2008's " The Dark Knight " earned over a billion dollars worldwide by itself -- both