As one might imagine (and I may have read it somewhere as well), after the PoA movie, should they decide to continue doing the movies, they very well may have to recast most (if not all) the non-adult characters. Why? Because with how long it's taking to put the movies out, the kids may have "aged out" of their roles by then. Not a definite, but certainly a real possibility.
How would you feel about that? I would imagine a good number of people have grown attached to certain actors in certain roles (the actors who play Malfoy and Ron, for instance). What would it be like to watch a Harry Potter movie (particularly the fourth movie) with new faces? Would you still go to see it and enjoy it or would it not be the same for you?
I think, for me, it would be tough, as I've gotten used to (and like!) a good number of the young actors in their roles. However, when you read the books (and particularly, if you read them before any of the movies came out), you may have *imagined* different faces to all the characters anyway! I really wish the people playing the roles could all stay, but I still think I'd go see the movie simply for the enjoyment of the story. What are your thoughts?