I think around the completion of the second Harry Potter film, Harry Potter and the Chamber of Secrets, director Chris Columbus hinted that the three main actors, Daniel Radcliffe, Rupert Grint and Emma Watson, would not appear in all of the remaining films in the series. He didn't specify why, but he did say age was a major reason. Seeing as how the actors would be out of their teens by the time of filming the seventh and final film, there's always been speculation that the lead roles would be recast.
Well, now with a couple of reviews online for the fifth film, along with a story confirming Radcliffe will be in the final two films, I'm starting to really question the validity of rumors about Watson and Grint not being in the final two films. And I definitely don't buy the age issue.
The buying audience for these films has come to know these actors as the characters they've played in the films. This audience is not stupid and can tell if a recasting has happened. (So far, the only character recast was because of its actor's death.) Radcliffe is Potter, Grint is Ron Weasley and Watson is Hermione Granger. We've seen them grow and have grown attached to seeing them grow. At this point, with their characters aging, we understand that their voices and bodies have changed. So why in the world would you want these people replaced because they looked slightly older than the characters they portray?
There are plenty of interesting stories in show business about playing up age and playing down age. Sean Connery and Harrison Ford played father and son in Indiana Jones and the Last Crusade, but are only twelve years apart in real life. Tobey Maguire perfectly portrayed teenager Peter Parker in Spider-Man even though he was 27 at the time. Earle Hyman and Bill Cosby convincingly portrayed father and son on The Cosby Show, even though they are eleven years apart in age in real life. The list goes on and on. The point is, age in show business has some wiggle room.
I can understand replacing the leads if the Harry Potter series took place over a year or so storywise, but we're talking seven years here folks. No matter if they got the best actors in the world to replace Grint and Watson, they would not be Grint and Watson. Say what you will about their acting talents, but the films work because the chemistry between the three works on film. I get the feeling it's just a matter of signing new contracts and being done with it. Besides, there were rumors that Gary Oldman would not be in Harry Potter and the Order of the Phoenix because of money disputes. Amazing what can change when these things work out.