I haven't read past the second book in the Potter series (though I've been keeping up with the movies on DVD and generally enjoying them), so I'm not particularly invested in how the last book winds up. But if you are, and can't wait till the book is released, head over to Christopher Bird's LiveJournal, Tetsubo Productions. He appears to have gotten his hands on a pirated advance copy, and has summarized the entire plot, chapter by chapter. Be warned, though, if you are invested and don't want to be spoiled, don't click, since these spoilers appear to be legit.