Iron Man 2 isn't slated for release until 2010, but it's already almost completely cast. Robert Downey Jr. and Gwyneth Paltrow will be the only major cast members to be returning. Woman beater Terrence Howard has been replaced as Colonel James Rhodes by Don Cheadle and Sam Rockwell will play Justin Hammer. Also signing on to the project are "The Spirit" co-stars Scarlett Johansson and Samuel L...