Leaked copies of the book are now available to download if you know where to look. Rowling's publishers refuse to confirm or deny if it's the real thing, naturally making everyone think it's the real thing. I would recommend buying the actual book, however. The 'leaked' copy is a pdf file with photos taken of every page*.
*Not that I've seen it of course, I wouldn't do a naughty thing like illegally downloading something.
