I've posted this on another thread but I'll post it here too. Its how I think the Joker might pan out in Nolan's World.
stage one: The Joker is a criminal who leaves cards and wears clown masks with his crew. During a bank robbery, the batman somehow lashes his face.
stage two: The deformation left him with a sadistic sense of humor. A year or so later he reemerges dressed and painted like a clown. He becomes obsessed with hysteria and anarchy in Gotham, he also becomes incredibly interested in the batman, all this with a sense of humor that his goons don't even get. Somehow at the end of The Dark Knight, around the same time Harvey Dent is scarred, the batman brawls with him and ends up throwing in chlorine or chemicals. Batman barely escapes. Gordan says something to batman along the lines of "before- the crime in this city could be bought, it was part of an organization you helped bring down.... They are all dead. Now Gotham is left with maniacs. Men that the cops can't understand... but they think you do. They believe you can... and you only made them bleed." The End.
stage three: The Joker makes his return in the third Nolan Batman film. Now completely pale head to toe, his red lipstick stained only around his lips and faintly around his gash, the dark around his eyes diffused a bit but permanent, the bleached green hair, also permanent. His white face, now scarred, looks grayish. He becomes more obsessed with the batman and has little recollection of his life before the dark knight entered Gotham.
This would leave the hype around what the Joker would look like in the third equal or greater to the hype he holds now. Fun times.