They haven’t even released a second movie yet, but already there’s talk of a fourth. TheWrap.com reported earlier today that Summit Entertainment was deep in the planning stages for Breaking Dawn, the fourth book in Stephenie Meyer’s hugely successful Twilight series. But not so fast, says Twilight screenwriter Melissa Rosenberg, who is still working on her script for Eclipse, the third in the teen vamp franchise (the second, New Moon, is currently shooting in Vancouver). “The most I’ve heard from Summit is ‘re-read it and start thinking about it,'” says Rosenberg, who is completing her show-running duties on the fourth season of the Showtime series Dexter. More telling, she hasn’t yet received one of the manifestos Meyer famously puts together before Rosenberg begins turning one of her books into a movie. Another source is also skeptical that Summit is far along in developing a fourth film. “As far as I know, Stephenie was still having meetings asking, ‘Can we really make this into a movie?'” The fourth book’s racy sex and explicit birth scenes make it less pre-teen friendly then the three earlier, more chaste romance novels. Summit, for its part, has no comment on the current status of Breaking Dawn.