Because it's the current trend. Look at Batman, Superman, Star Wars, etc. Every studio wants someone they don't have to pay tons of money, someone who they can say they 'made', things like that. Of course actors like Bale have had amazing parts before, but he wasn't very established before Batman, like Mark said (although Equilibrium is one of my all-time favorite movies). And, no, the rest of the actors weren't exactly established before playing Bond. Take a look at their movies before playing James Bond: - Pierce Brosnan: http://imdb.com/name/nm0000112/ - Sean Connery: http://imdb.com/name/nm0000125/ - George Lazenby: http://imdb.com/name/nm0493872/ - Roger Moore: http://imdb.com/name/nm0000549/ Yeah, they've all had roles before, but none of them were exactly superstars.
I agree with Omar A. Clive Owen. EDIT--Christian Bale had strong roles in both Swing Kids and Dead Poets' Society, never mind Equilibrium, before Batman Begins.
If Orlando Bloom is a joke as being Bond, then Ewan McGregor is a Dane Cook stand up performance: insanely hilarious. Nah. I keep seeing Clive Owen as Bond. mmm.