Regarding our original concept of good vs evil clowns, we still wanted to blend some sort of comedy into the piece, whether it was slapstick or just plain black dark humour. I feel that it was summed up best by this image of Heath Ledger's Joker in a female nurse's outfit, as it mixes the best of both. His dark maniacal nature, and the staple of a clown in an outfit that comically contrasts his true nature (e.g. when a clown goes to bed at night as a regular person again).
There is no bad Joker! I think both the scripts have been written very interesting, and the actors have both been working like crazy to become the Joker, which they did awesomely!!! So thank you, story writers and actors for being so wonderful.