Bruce Willis and Sean Penn have joined the cast of veteran director Barry Levinson's upcoming comedy What Just Happened? John Turturro and Kristen Stewart have also signed up the picture that Robert De Niro will lead. More info from Variety... In the fictional film, De Niro plays a desperate movie producer trying to preserve some dignity as his soul is slowly destroyed by the machinations of Hollywood and the breakup of his second marriage. Pretty neat idea for a movie, and an extremely impressive cast. Especially the addition of the awesome Sean Penn who has really been on fire with his dramatic performances over the last decade. It's been a while since he has done comedy, but his public image after the failure of All The King's Men might indicate that it will do him some good. Shooting is set for March. source - coming soon, variety