From Deadline:

Edward Norton has been set to star in Birdman, the dark comedy that will be directed by Alejandro Gonzalez Innaritu for Fox Searchlight and New Regency. Norton joins Michael Keaton, Emma Stone, Naomi Watts and Zach Galifianakis in a film that will be shot in a Broadway theater in New York beginning mid-April. A former actor (Keaton) who once played a superhero puts together a play on Broadway that is based on a short story by Raymond Carver. Unfortunately, the ex-superhero’s plans to soar again are threatened by his egotistical lead stage actor. Norton will play that actor. Birdman is produced by Inarritu, John Lesher and Robert Graf. The director wrote the script with Nicolas Giacobone, Alexander Dinelaris and Armando Bo. While Norton is as identified with serious dramas as much as Inarritu (who’s making his first comedy), this will be the actor’s third straight film with a comic sensibility.