Casting has apparently already begun, and the series will debut sometime this year.
Profile from Dark Horse: http://www.darkhorse.com/profile/profile.php?sku=11-820
a review: http://thecomicqueen.blogspot.com/2004/09/amazing-screw-on-head-review.html
For those of you who haven't read it, Screw-On Head is cool beyond words. He's a secret agent for the U.S. Government working during the time of the civil war. It has a great Jules-Verne-y style to it, all the more accentuated by Mignola's environments. Think of it as Atlantis: The Lost Empire except as a parody of itself. Great stuff.
I've also saved Helen's 52 acting notes by Ed Hook. Download them here
Angelfire's a bitch and won't allow you to direct link: just copy the URL and paste it.