Elizabeth Reaser will co-star in Jason Reitman’s latest film Young Adult, which also features Charlize Theron (Kristen Stewart’s co-star in the coming Snow White and the Huntsman).  The film has been given a release date of December 16, 2011, by Paramount. Details from The Playlist:

Paramount smells a winner and have pegged the director’s next effort, “Young Adult,” with a prime limited release bow on December 9th with a wide release to follow on Decmeber 16th—it’s more or less the same frame that “The Fighter” got into the ring with last year. But for those expecting the breezy charms of Reitman’s past efforts, they will be in for a shock. Once again reteaming with “Juno” writerDiablo Cody, this decidedly darker and more mature film, stars Charlize Theron, Patrick Wilsonand Patton Oswalt with J.K. Simmons narrating, and follows the story of a divorced 30-something young-adult fiction writer (Theron) who returns to her Minnesota home to chase after her now-married-with-kids ex-boyfriend (Wilson) with Oswalt playing a semi-crippled old high school acquaintance who befriends the narcissistic and misguided female. It will certainly be Theron at her most unlikeable and the film will be a side of Reitman and Cody we’ve not quite seen before.

The article suggests the film also may screen at Venice Film Festival and/or Toronto International Film Fest.