Filming begins next month for Shane Black's iron man 3, and casting details for the next installent of Marvel's popular movie franchise have begun to be revealed. We know that many of the regulars have signed on to return, including Robert Downey Jr. as Tony Stark, Scarlett Johansson as Black Widow, Gwyneth Paltrow as Pepper Potts and Don Cheadle as Lt. Col. James 'Rhodey' Rhodes. A couple weeks back it was announced ...