Rachel McAdams would probably give the role the much needed spunk it would necessitate (something Kate Bosworth sorely lacked).
She didn't get many opportunities to show it, but I thought Bosworth displayed plenty of spunk in the early scenes on the plane and in Perry's office. Unfortunately I think most people just have a hard time seeing anything past her young appearance.
I would DEFINITELY love to see McAdams in the role though. She can be tough when she wants to, she's about the right age, and she's cute as all hell.