Frank or Francis
The Pitch: This one's a musical-comedy - a Hollywood satire in which an auteur director (Frank) and a movie blog commenter (Francis) go to war with one another. Francis hates almost every movie he watches. For a more spoilerific summary, you can check this post.
Unfortunately, the project has struggled to find funding, and at this stage it looks like the film might not happen.
Director: Charlie Kaufman
Cast: Unknown, though the following actors were mentioned before the project seemingly fell apart. Jack Black (Francis?), Steve Carell, Kevin Kline (Richard / Richard's Head), Catherine Keener, Paul Reubens, Elizabeth Banks.