My main problem with this, and the idea that Mr. J is an escapee from Arkham ,is that in the trailer we see Gordon say "no name, no other alias" as if they just cant finger who he really is-if he came from Arkham they would instantly go "oh, its THAT guy"....I really like thinking that we never know how the Joker becomes the Joker-he's a complete mystery! Any time you try to explain how a guy becomes evil (cough, halloween remake ,cough) its always a disappointing "waaaah, he was abused by his parents, and bullied , and waaaah, this one night this one thing happened waaah" which I think robs them of a bit of credibility-if we have no origin story the Joker can do anything, any crazy messed up plan than could slaughter thousands with sick demented glee, and if we dont know whyhe's doing it or how he got like this the audiences imaginations will be fired up with "what the hell happened that guy that made him SOOOOOO crazy?"
plus Mr. J is the counter point to Batman right? so we the audience know that Batmans costume is his real identity, we are privy to the information of how he came to be etc etc? well, then Mr. J should be the opposite and yet the same-he too wears a costume that is his real identity, but we dont know where he came from, we dont know his motivations, and we dont know what he's capable off....
plus Mr. J is the counter point to Batman right? so we the audience know that Batmans costume is his real identity, we are privy to the information of how he came to be etc etc? well, then Mr. J should be the opposite and yet the same-he too wears a costume that is his real identity, but we dont know where he came from, we dont know his motivations, and we dont know what he's capable off....