Yes, the popular TV show is getting its own cartoon in Japan. While giving American characters their own shows in Japan isn’t as surprising these days (Wolverine and Iron Man are also getting Animes) I wasn’t expecting this particular show to get adapted. Though I do like it (and nobody’s more surprised than me; I don’t like Horror in general, but the show is so well written, acted, and even at times damn FUNNY I can’t help but watch it.) Not sure about the Anime, though- Dean looks like a dork if you ask me. 
Besides Monster-hunting-in-a-modern-world is hardly original for Anime; Demon City Shinjuku comes to mind.
Still, for fans of the series this is another chance to revisit the characters (the series will adapt the original episodes). More details here: http://spinoff.comicbookresources.com/2010/10/08/watch-the-new-longer-trailer-for-supernatural-the-animation/