many people have have noticed that actors Joseph Gordon-Levitt & Heath ledger look very similar, and perhaps so did chris nolan.
In the third trailer for inception Joseph Gordon-Levitt is in post movie title scene.
Inception Official Trailer #3 (Leonardo DiCaprio)
Leo Inception™ | MySpace Video
This leaves me to believe that Joseph Gordon-Levitt will be the joker in the dark knight even if a cameo.
chris nolan has a history of recycling his actors as seen with christian bale and Michael Caine being in both "the prestige" & " The Dark Knight " so why not use Levitt as the joker?
what do you think?