You know, over the past few days, the casting of Ledger as the Joker has really started to grow on me. I know Nolan wants to go for a much darker joker, and one very different from Nicholson's or the animated Hamill version. I think he'll be a damn good Joker and breathe new life into the character.
Here are some excellent photoshops I found that help give us an idea of what he might look like.
This one's definitely my favorite so far. Nevermind the clothes, I just love the grin:
not a huge fan of this one, but still helps me see him playing the part
A little closer to the traditional Joker...
This one I like a LOT:
As of now, I'm happy with the Ledger casting. Now they'll just cast Liev Schreiber as Harvey Dent, I'll be satisfied.
EDIT: my new favorite. A very sinister Joker that I think would fit right into Nolan's gritty universe. Just loose the long hair (I think the original pic is from the 10 Things I Hate About You)