According to Spoiler TV, they've cast the person mentioned in
this post. What's your opinion? Who would you have picked?
A "Supernatural" source has confirmed that the ubiquitous and talented Mark Sheppard (the actor who has his own Full Employment Act) will play a "pivotal" crossroads demon named Crowley in Episode 10 of the season. The episode is called "Abandon All Hope...," and it was written by Ben Edlund and will be directed by Phil Sgriccia. It's the final "Supernatural" episode of 2009 (the show will resume its fifth season with new episodes in 2010. More than a month without "Supernatural"? Say it ain't so!). The episode is "epic" and will "definitely ... have the fans on the edge of their seats going into the holiday 'hellatus,'" my source said.
IMDB of said actorOriginal Article (The relevant bit is towards the end)