The film tells the story of a married couple -- Aniston and Rudd -- who leave New York to escape modern society. They find themselves visiting a commune, and that's where Hahn's character comes into play. She's one of the members who welcomes them.
The addition of Hahn is great. It seems like she shows up in films randomly, and whenever she does, it's hilarious. Plus, we all know how funny Hahn is when she's brainwashed. Remember this moment of "Sweet Child of Mine" in Step Brothers? Classic. It definitely gave us all comedy boners.
Regarding Wanderlust, I think this is really shaping up to be a riotous film. Sure, Aniston tends to play the same character in every movie she's in, but after Role Models, I Love You, Man and all the other funny flicks he's made, Rudd is like the king of big screen comedy and I'm sure he's gonna shine in this. And after Marino's hilarious stint on Party Down, I can't wait to see what he's capable of as a writer.
Currently, Hahn is in a guest arc on HBO's Hung, recently finished filming My Idiot Brother with Rudd, and has a part in December's How Do You Know.