Kyahahaha~.
Brad Swaile, my sexxy voice love(r). Ever since he was the bestest Light ever I've decided I want him to act as everyone.
I'm just kidding, people. I mean, about him being Terra. Also, I certainly do not want anyone affiliated with the English Naruto to act in Kingdom Hearts. I can't stand that dub. But that's just my opinion.
I think this is going to be an interesting choice to make. Square seems to enjoy casting actors associated with Disney for the main protagonists in the KH games, but since there hasn't really been an adult main character before in KH (Leon doesn't cut it; sorry), it might be tough to find someone who can fill the role. Especially since Disney is mostly comprised of kid actors with the spotlight rarely focused on adults. I guess I'm only thinking of the Disney channel though. Movies are an entirely different story.
Personally, I wouldn't mind someone like Kent Williams (Hatori in Fruits Basket, several characters in Dragonball Z such as Android 20 and Dr. Gero, and Count Gyula in Trinity Blood) to try out as him. I would absolutely love Square forever if they casted Laura Bailey as Aqua. I mean it. I would adore them.