Jim Dale, the voice behind Harry Potter talked recently about the hope that no leaks will happen from Harry Potter and the Half-Blood Prince, as this will ruin the magic for the fans. He also discusses being recognized as the voice by children and how he came up with the voice of Harry Potter. The article does contain a spoiler about the book.
Mr. Dale on creating the voice of Harry:
Well, Harry. I decided in the early days, instead of trying to switch to a voice of Harry, just use my voice, a younger Jim Dale. And over the years, as Harry has aged, then I've allowed my voice to become a little more normal.
You can watch the video here.
Remember, Mr. Dale will be reading from a Harry Potter book tomorrow morning on the Today Show.