Penn has officially joined the cast of What Just Happened?, the adaptation of Art Linson’s insider look at making movies in Hollywood, mostly focusing on putting together and shooting The Edge. Which was a good movie but would have been better had it featured the guitarist from U2 fighting a bear instead of Hannibal Lector.

Bruce Willis, Stanley Tucci, John Turturro and Kristen Stewart have also come aboard – at least a few of these people (like Penn) will be playing themselves in cameos. Robert DeNiro is playing Linson – a funny little inside joke, since trying to get DeNiro to star in The Edge is a major point in the book.

Barry Levinson is directing the film, which is supposed to shoot starting March 22. Levinson has not been on the top of his game for a decade, but this is a terrific cast – and for once DeNiro is doing a comedic role that isn’t self-parody. My fingers are crossed for this one to be at least worth sitting through.