I hear they want to cast someone young so as to attract younger audiences, probably a feeling of competition with films featuring young protagonists like Spider-Man. I hear that Ioan Gruffud (Black Hawk Down, King Arthur, Fantastic Four and Horatio Hornblower) is a contender along with Gerard Butler, Eric Bana and, the guy they've been carting for years, Clive Owen.
Hugh Jackman recently counted himself out of the 007 bid, or so I've heard.