Biel will play the character originally played by Vera Miles. The actress played Lila Crane, and managed to escape the hotel in the Psycho finale. Johansson will play Janet Leigh--instantly, the shower scene comes to mind when thinking of this movie--the character Marion Crane is stabbed to death.
The movie is said to start filming sometime next year. This should be interesting, because I don't think anyone can touch Hitchcock.