Well, I have discovered that said book is now available for pre-order on various web-based shops. Therefore it must be real!
Here is the link for the book on Amazon:
(It is obviously available from other shops as well...)
The official release date is the 2nd of May, but you can pre-order it from now.
I can't describe how excited I am about this coming out.
If any of you happen to buy it, I really hope you enjoy it.