Rachel McAdams, the new Black Cat.

I personally think that she is a great candidate for it.  As long as she can pull it off.  Black Cat was not really a villain in the original Spiderman series.  She was villain in the beginning, but later became an ally of Spiderman.  There is probably something going on between those two...wait, not probably.  There IS something going on between those two!!!  Spiderman is such a player...

By the way, if you don't know who Rachel McAdam is, she was in Sherlock Holmes, The Notebook, State of Play, or Mean girls as the head cheerleader.