The film, which goes by the name of The Chadster, was originally going to be produced and directed by Todd Phillips (you might know his name from The Hangover), but Phillips has dropped out of directing though he will still produce.

From Pajiba: "The studio wedding comedy, set up at Warner Brothers and produced by Phillips’ Green Hat Films, is about a best man who has his position threatened when an eccentric, long-lost childhood friend shows up at the wedding and causes trouble."

McBride is playing the eccentric friend of course.

Aside from this project and the forthcoming second season of Eastbound & Down, McBride and Harwell are also working together on Hench, a comic-book adaptation about a football player who suffers a career-ending injury and goes to work as a henchman for a villain.  Sounds like it has potential, as does The Chadster if McBride's character is anywhere near as phenomenal as Kenny Powers.  Also taking bets on the best man being uptight and learning to relax and have more fun with life by the end of the movie.