Pirated or not, the leaked version will not make A dent in HP's sales. Most of the fans who downloaded the ebook would probably get a print version too as an ebook is not a 'collectible' and true fans just have to have the physical form of the book.
HP5 was copied, proofed, and uploaded in quick fashion too...If I'm not wrong,, it was HP5 that make distributed scan/proofread mainstream for must-have books.
I believe all six HP books exist in ebook format somewhere, but unlike movies or music, ebooks are still not as easy to read as printed books. Save for portability, printed books still gives a better reading experience (except when reading under the sheets with a flashlight). Pirated HP ebooks hasn't stop Ms. Rowling from becoming the richest person in UK (net worth $1B and increasing with every book sold), eclipsing the Queen.
Still, I will buy a printed copy this coming week. Ebook availability or not. I was just wondering if buying a printed copy will allow me to keep a electronic copy on my PDA... does fair use allow that?