Take a look at the statement released by LucasFilm.
"As pre-production of Star Wars: Episode VII begins, Lucasfilm has confirmed that award-winning writer Michael Arndt will write the screenplay for the new Star Wars film. As revealed in the ongoing video series posted here on StarWars.com, Kathleen Kennedy and George Lucas have begun story conferences with Arndt. Arndt won an Academy Award for Best Original Screenplay for writing Little Miss Sunshine (2006), and was nominated for Best Adapted Screenplay for writing Toy Story 3 (2010).
Michael Arndt also wrote upcoming movies such as The Hunger Games: Catching Fire and Oblivion, both set for release next year. Now that the question of who will write Star Wars: Episode VII is out of the way, the big question is who will direct? Will it be previously-mentioned candidates such as Matthew Vaughn or Colin Trevorrow? Will another filmmaker come out of left field to snatch the coveted gig? Stay tuned. You'll know as soon as we do.
Star Wars: Episode VII comes to theaters December 18th, 2015 and stars John Boyega, Daisy Ridley, Carrie Fisher, Harrison Ford, Mark Hamill, Adam Driver, Domhnall Gleeson, Lupita Nyong'o. The film is directed by J.J. Abrams.