We've heard that in the movie, Susan will fight at both the Castle Raid that takes place in the middle of the film, and the battle at the end.
This makes me wonder if Susan will stay and fight with the boys while Lucy goes off alone with Aslan. I really don't like this idea.
Susan fighting is so incredibly the opposite of her character. And that idea works the other way too. If I heard that Peter was NOT going to fight in PC, I'd be pretty upset.