Harry's ambiguous morality is one of the things I like best about him. Most readers probably don't notice it at all because we're so used to seeing everything through his eyes and thinking of him as the hero, but I love that it's there. It means he's not perfect. I HATE it when the hero is perfect and always right and has this unerring moral compass. That's the reason I really fear that she'll make Snape OMGTEHEVIL in the last book. It will reveal that H. has been right all along, and will almost give justification to all of his other actions. He really will be the perfect chosen one. He won't have distrusted Snape out of pettiness and generation-spanning rivalry; it will be because he somehow knew that Snape was bad all along. It would change the whole tone of the books and take away one of Harry's actual believable character traits.