I think Johnson should be played by Samual L. Jackson, Cortana by the lady that normaly voices Cortana, The Arbiter by the guy that voices him, Orlando Jones as a random soldier that follows Master Chief for a short time for comic relief and comes back later in a sequal or something, George Cloony as Cpt. Keyes, Sarah Michell Geler should be Cpt. Keye's daughter and the guy that normally voices MC and Arnold Schwarzeneger as Master Chief thx