It was not unexpected. Of course someone would leak "HP7" onto the net in some form or another. Other than the repeated hoaxes of a leaked pdf or text file of the novel (which usually contained nothing more than a popular - and long- fan fiction) someone actually did leak the entire novel. But how?
They guy took photos of every page. EVERY PAGE. 396 images.
If you look around at all the popular places it's not hard to find at all. It's remarkable to me that someone could take the time and expend the effort to take all those photos and then upload them to the IntarTubes. But what a desideratum this guy made eh? Apparently, if rumors are to be believed, the guy that took the photos works at a library and (again, this could be apocryphal) libraries could open the boxes containing the books early so they could catalog them and place the protective jackets on them and all that fun stuff. I mean it doesn't take that long to snap off...
396 images. Geepers.