who exactly is goin 2 play rennesme on the last movie

Summitt is still in talks with Stephenie Meyer over Breaking Dawn and they havent 'official' sagte if oder when they're going to do it...so they havent even begun to start casting. I also read something that Nessie would probably have to be done CGI and that was worrying Stephenie because she doesnt want her to look 'fake'.