From TVGuide.com

Question: Any scoop on Dead Zone? I’m a longtime fan.— Snow
Ausiello: Major-ass prattle alert! One of the three major male actors from the original Dead Zone film is guest-starring in the season finale. If you can't remember who else aside from Christopher Walken was in the thing, you're in luck: Here's a handy-dandy link to the cast list.

Way cool Bjossi! Thanks for the info. I hope it's Martin Sheen.

I'm holding out for Christopher Walken, but somehow I think it's Tom Skerrit

Well if the episode title puzzle holds true then Christopher Walken would make an awesome Herb Smith. I know Michael Hall and others have said how much they've wanted him to guest star on the show.

I hope it will be Chris Walken, that would be totally awesome for everyone involved in making The Dead Zone and the viewers.

Thanks. Sounds exciting. I will definitely keep watching. I think the writers are trying to lull us fans into
complacency and then they'll hit us over head so to speak with something we totally unexpect.

As awesome as it would be, I'd assume it isn't going to be Christopher Walken since they said take a look at who else was in the movie.

I'm looking forward to it!

Christopher Walken would be awesome. I imagine though that to get him on the show would probably cost big time, unless someone personally knows him and asks him as a favor.

If I were a betting person, I would say that it will probably be Tom Skerritt! In "Babble On" we were introduced to the character Herb and so they have to stay pretty close to an actor resembling him. Yes, and age would play a part. Herb's age would be 69. In "Interred" at the cemetary wasn't Herb's birthdate 1938? Tom Skerritt has the look that would be believable as Johnny's father. Martin Sheen would be great too.
IMO Still I would bet that it is Tom Skerritt!

Either of those two would be great too. But I would love to see Chris Walken do a guestspot, that would be truly awesome.