In the book The Art and Filming of the Dark Knight Trilogy the only concept artist mentioned by name is Jamie Rama (Transformers, Super 8, X-Men: First Class). He's one of the best in the business.
He shared some of his concept art for the film The Dark Knight (2008) on his site.
@ 2008 All images copyright of Warner Bro. Studios and the artist
See more of Jamie Rama's portfolio at jamierama.com and read my interview with him Jamie Rama Talks About Retro 'Super 8' Concept Art and the Biggest Mistake an Artist Can Make
What do you think of the illustrations?