Who would you like to see appear in the next Batman film?

Black Mask and Hugo Strange would be perfect villains for the next film. Neither of them are big name characters, but Black Mask is the perfect evolution of crime in Gotham City - A hybrid between the two, distinct types of criminal, gangsters and 'freaks'. Seems the logical choice considering Nolan's emphasis on 'escalation' at the end of Begins... Hugo Strange is perfect because, given the end of the Dark Knight, a villain such as Strange, who is utterly obcessed with Batman, would be in his element. Who better to find him than somebody who, in the comics, eventually, discovered Batman's identity through a grim fascination with him?