I vote Bruce Campbell for Zed. He's not old enough, but with the magic of makeup...
Joking aside, I think Christopher Lloyd would be perfect as Zed. I do have to wonder whether Raimi will do something about the rather absurd plot point of the ban on fire from the first book (I never understood how that was supposed to work...) and whether he'll be able to get away with some of the more extreme stuff in the series. Darken Rahl's torture of the young boy, Richard's torture (on various occasions), the whole dominatrix-as-bodyguard thing, various rape scenes, cannibalism... The first book was pretty light on that sort of stuff, but I'd think it would be an issue with whatever network this airs on if he goes on with the rest of the novels.
I'm kinda surprised, really. I would have expected a Wheel of Time series long before Sword of Truth. Maybe it's just because Goodkind actually has a contracted end in sight for his books.