Sidenote: this must be why Sony partnered with Pottermore last year, not for any ebook trick.
It turns out that this is only vaguely related to ebooks (but the tech is still interesting). The game is going to feature original content written by JK Rowling as well as new and fun activities that make use of the motion-sensitive controller on the PS3. Players will compete in the game by learning how to cast spells, conjure up visions, and learn the secrets of wizardry - just like a student at Hogwarts.
It's not clear from the announcement, but the Wonderbook appears to be a new accessory for the PS3. Going by the video posted here, it looks to be some kind of anchor point for the augmented reality aspects of the game. The PS3's camera will track your movements (and that of the controller) and, depending on you casting the spell correctly, the PS3 will show on your TV screen the results of the spell you just cast, and it will make it look like the magic is right in front of the player. The image above shows what the kid would see on the screen.
If I'm correct then Book of Spells is game which will use Wonderbook and is likely sold separately.
J.K. Rowling said, “ This is an extraordinary device that offers a reading experience like no other.” No shit. This isn't a reading experience; it's a game. While many confuse the 2, I can see the difference.
The game and accessory are due out in November 2012, and I'd expect them to have rousing success. Kids will love it and parents will buy it because they'll think it's reading. That's fine, but like enhanced ebooks this likely won't improve literacy. Eye-hand coordination, on the other hand, will go through the roof.