This is a small thing, but what Atrios is talking about here (the Americanization of the first Harry Potter book) really is bizarre and somewhat frightening to me. It's similar to putting English subtitles underneath people who are already speaking English, but have heavy-but-understandable accents because English isn't their first language. And I can't help but feel it's connected to the mania over illegal immigrants not speaking English -- the idea that we should be at all inconvenienced by a moment of linguistic incomprehension in our lives seems to offend us on some level, I guess. I wasn't aware that the point of a book, or a television news program for that matter, was for the audience to engage their eyes, ears, and brains as little as possible.
And it's totally irrelevant now that the Harry Potter cycle is complete, but you could always get the unbowdlerized Rowling in Canada -- Amazon.co.uk wasn't necessary.