We have an update on Supernatural's production status. According to The Vancouver Sun and Playback Magazine, Supernatural will shut down on December 5th. That date is tentative, as per Don Cott, vice president of the Canadian affiliate of the Alliance of Motion Picture and Television Producers. Playback Magazine also referenced the cinematographer's union as a source.

Like a number of other shows, The CW's cult hit is filmed in Vancouver, and employs several hundred Canadians. The series follows two brothers, Sam (Jared Padalecki) and Dean Winchester (Jensen Ackles), as they hunt demons, ghosts and scary urban legends. The website Digital Spy says that ten episodes of Supernatural are in the can and they are finishing off production on two more, so viewers should get to see twelve episodes at least. Episode 3x07 just aired, and epguides.com lists the next episode on December 13.
Those five additional scripts the series reportedly has stockpiled may be filmed soon or not, depending on what develops with the strike.

As the WGA strike continues, more and more series have been closing down. The main issue here is fair compensation for use of the writers' work on the internet. TV writers are getting no residuals on itunes and other internet downloads, or on streaming video. The AMPTP claims that episodes streaming on network websites are advertising, but ads are embedded into the episodes. Writer residuals on DVD's are also very low -- the rate was set back in the 1980's to allow the DVD revolution room to grow. Writers were promised a raise, but it never happened.

Supernatural is a show with a dedicated viewership, and hopefully has a good chance of surviving a longer then usual strike-induced hiatus.

Sources:
Variety
The Chicago Tribune
Playback Magazine
Vancouver Sun
Digital Spy