Jonathon Rhys Meyers is Valentine.
Okay, so I never thought I'd say this, but.. I'm a little attracted to Valentine right now. Huh. Weird. If you don't know who Jonathon Rhys Meyers is.. crawl under from out that rock and go watch some movies! He's been in many well-known films, such as Bend It Like Beckham, Mission: Impossible 3, August Rush and Albert Knobbs. He also played King Henry VIII in the show, The Tudors. If you wanna know about any more projects he's been in, here his IMDB page.
I've gotta admit, I definitely didn't picture Valentine look him at all (I pictured him like.. maybe Paul Bettany kinda?) but hey, I'm not complaining one bit. And he is a brilliant actor, to say the least. The guy's been nominated and has won heaps of awards, including a Golden Globe.
Now the only people (I think) that are left to be cast are Alaric and Raphael! WOO!