Leterrier said that the role of Bruce Banner, played by Eric Bana in the first film, is close to being filled and the rest of the cast will follow soon after. "Thunderbolt" Ross is the main villain with Emil Blonsky (aka Abomination) not far behind. The Hulk will be CGI with prosthetics used in certain scenes where needed. The title character will also show feats of strength.
Louis Leterrier
CGI Hulk