Wood and Stone were both forced to drop out due to schedule conflicts and as of now, only Abbie Cornish and Vanessa Hudgens remain out of the original line-up, which was always in negotiation anyway.
But don't despair, because every casting report gives us a bit more of its grindhouse plot. According to The Hollywood Reporter, Malone will be playing Cornish's younger sister, both of whom have the unfortunate luck to be locked in this hellish mental institution. Chung will be playing Annie, "a country girl with a big heart." (I want to add "as big as all Texas" but I'm not going to jump to geographical conclusions. Maybe she's from West Virginia or Tennessee.)
There's not much more to say about the casting, except that I'm glad to see a little diversity by way of Chung, and I'm uncertain about Malone. She's certainly a very respectable young actress (and co-producer these days) but she always comes off so brittle and humorless. Maybe all she needs is a part like this where she can cut loose and have fun ... and how can you not have fun with a film like this? It's a laugh just writing about it.