I do not think there would be a Midnight Sun movie made without Stephenie's involvement and if she were involved information would be on her website. The last comment that I heard her make regarding Twilight is that she is over it, and doesn't have a desire to reenter the Twilight world anytime soon.
In an interview with Variety about her career, the novelist-turned-producer says she gets “further away every day” from the blockbuster book and film series.
“I am so over it,” continues Meyer. “For me, it’s not a happy place to be.”
Meyer admits the door isn’t completely closed.
“What I would probably do is three paragraphs on my blog saying which of the characters died,” she says, adding, “I’m interested in spending time in other worlds.”
Meyer is in the midst of promoting the Keri Russell film Austenland, the first movie to be released from her production company, Fickle Fish.
On the topic of Midnight Sun - the book
Meyer told the BBC, while promoting the release of her upcoming the film The Host, that once the Twilight movies began opening in theaters, she couldn’t continue to write Midnight Sun.
“It wasn’t something that I was in the middle of working on,” she said. “It was a project that I had been doing before. But I was working on the movies at that time and finishing up the last novel, and I was able to do that last novel without interference mentally from the film and the actors being the characters. But I could feel it seeping in more and more, and I wasn’t able to really get into the characters completely separate from the movie anymore, so it didn’t really feel like I could write it at that point, because it was a little tainted by that other vision.”
So basically the Edward that was in her head when she first wrote Twilight is gone and therefore so is his "voice". For that reason Meyers does not want to finish Midnight Sun.