Scarecrow is JOKER
I heard that the Scarecrow (Cillian Murphy) will be in the sequel. There is also word that the Joker will be Cillian's character.
"After being objected to his own Fear Toxin, Doctor Crane's mental state becomes exactly what he desires of his patients. As he begins to cope with his newfound insanity he begins to adapt a new personality. The Joker. He begins to paint himself to resemble life's personas. First fear, now terror. This new persona is basically used to beat Batman. His identity will not be revealed until the film's climax but Cillian's character will be featured as a background character."