Vulture claims that Oscar winner Michael Arndt (Toy Story 3, Little Miss Sunshine) "has written a 40- to 50-page treatment for the film and is likely to be at least one of the writers when the Disney/Lucasfilm project begins shooting in 2014." They say Luke Skywalker, Princess Leia and Han Solo are indeed in it.
Furthermore, Vulture hears "Arndt's 40-something page treatment will soon be crossing the desks of top directors, including Brad Bird, Steven Spielberg (Lucasfilm's co-chair, Kathleen Kennedy's former producing partner), and J.J. Abrams. Whether they'd be interested is unknown (Star Wars is a lot of baggage for an established director), but Disney wants to make sure they've at least tried the biggest names."
Arndt also co-wrote the screenplay adaptation of The Hunger Games: Catching Fire, which is currently in production.
Sounds like things are really starting to take shape over at Disney and so far I'm liking what I'm hearing. Main characters are coming back and thus far Hamill, Fisher, and even Ford are all at least interested in returning to their prior roles. I'm remaining hopeful that we'll see one of these directors pick up the project as well and this thing can really take off. Harrison Ford has a pretty good standing relationship with Spielberg so if he takes up the director's chair that could be a good sign that we'll see Ford back in action.