A couple of weeks ago, and to no surprise to Batman fans, Christopher Nolan officially signed on to direct the Dark Knight sequel. Nolan is notorious for being tight lipped on his projects, but that doesn’t keep the rumor mill from churning out gossip all over the world wide web.
Batman 3 is one of those movies that is going to continue stirring up rumors (despite even what the director says) until it's actually released. With the recent trend of filmmakers misleading their fans, no one believes them anymore when they make statements like "this definitely isn't in there" or "for sure".
Even when they're being sincere (like the thing about Harvey Dent that came out soon after Dark Knight was released) the fans think they might be misled. I don't think Nolan is one to do that. Sure he won't tell you what he's doing, but he won't necessarily lie about it either.