Well I've only seen Dakota Fanning play a 'darker' role in one other movie (Hide and Seek) and everything else I've seen has been a little on the 'sweet and innocent' side of things. The character of Jane in the Twilight saga is anything but sweet or innocent and Jane is an evil and twisted individual. It will be an interesting part for her to play. Will be great to see her in something as dark as this (assuming the script supports it).