The Batman Begins sequel (The Dark Knight) spoilers have started pouring in as elaborated below by comicbookmovie.com:

“SlashFilm was lucky enough to be in correspondence with a reliable source, who presented them with a whole host of juicy spoilers for them to sink their teeth in to and, vicariously, us too! Over the next few days more will be released, and whether any of them will turn out to be true will be left to history to decide, until we know otherwise, let the speculation begin”:

When The Joker (Heath Ledger) kidnaps Rachael Dawes (Maggie Gyllenhaal) from a big party, Dawes is forced to reveal Batman’s true identity, Bruce Wayne. Later, however, The Joker becomes convinced that Dawes lied to him when he encounters both Bruce Wayne and Batman in the same room together simultaneously.

I have no idea how Bruce pulls this off. I would assume that if a Batman impostor exists, Joker would likely be in on that joke. This causes Joker to think that Bruce Wayne is NOT Batman and that Rachel, in fact, lied to him… His accusation of her deception doesn’t end well.

Apparently there is an impostor posing as Batman who is running around Gotham City. The cops believe he is the real Batman and that he is on their side. How this plays into the big story is unknown. I know that this may seem very unlikely and improbable, but my source has not been wrong yet.