It's official: Lucasfilm confirmed the rumor on StarWars.com. Star Wars fan Michael Arndt, screenwriter of Little Miss Sunshine, Toy Story 3, and the upcoming The Hunger Games: Catching Fire, is working on the return of the Star Wars franchise with Star Wars: Episode VII.
"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." - per StarWars.com. The message goes on to say that producer Kathleen Kennedy and George Lucas "have begun story conferences with Arndt."
In other news, there's no word yet on who will be tapped to direct Star Wars 7. There has also been no official confirmation on whether Luke, Leia and Han will put in appearances in some form or another in the new Star Wars trilogy.