I'm trying to think how many times that's been done. NBC's The 10th Kingdom, that film w/ Amy Adams, Susan Sarandon and Patrick Dempsey, CBS's Jack and the Beanstalk...
Alan Dale has extensive genre cred, having played smallish roles in Star Trek Nemesis, the most recent Indy movie, and guest roles on The X-Files, The Lost World, and Torchwood. Plus he played King Arthur in Spamalot in London.