Katie Holmes played Rachel Dawes in Batman Begins but Maggie Gyllenhall played the character in The Dark Knight.
Was there any particular reason why Katie Holmes didn't continue on in the role?
According to Julie Polkes, a spokeswoman for Ms. Holmes,
But according to this article,
No one can ever know if her public statements were the real reason(s), but she supposedly turned down coming back so that she could be in "Mad Money".
See this MTV article.