Since I'm not a major Harry Potter fan, I don't really care how the series ends--so long as it does because I feel a responsibility to keep reading the things. However, these little hints J.K. Rowling loves to give out between books set my teeth on edge. To me, they seem like nothing but a marketing ploy, an attempt to keep interest high while she's working on her bloated manuscripts.
And why her obsession with killing people off and hinting about it between books? "Guess who will die--no, go on, guess!" Personally, I think there is a school of thought that believes killing off a character in a children's book is the mark of an "important" work. Expose the little nippers to the reality of life.
Death is not necessarily the hallmark of good writing.