Eric Bana will reportedly not return as Bruce Banner/the Hulk in the planned sequel, according to Cinescape.
That's in part due to the film’s exit from Universal and recent comments made by ex-Marvel Studios exec Avi Arad that the film (called The Incredible Hulk) will be a remake, not a continuation of Ang Lee's arty but not so well-received movie.
Reportedly, the Mummy's Brendan Fraser (!) is one of the names being floated as a possible replacement.