I actually don't think any actors in the films are the same age as their character's are supposed to be anymore. Look at Alan Rickman, Snape's supposed to be what, late 30's? Alan's 62! Lily Potter died when she was 21, Geraldine Somerville's 41 if I'm not mistaken. I'm glad he's coming back, I think it would be insane to switch actors we have grown accustomed to over the course of the past 8 years for the final film. Not to mention he's a terrific actor (see Doctor Who, Midsomer Murders, and the amazing movie Wilbur Wants To Kill Himself for proof!).