The Nikon D400 book: “Magic Lantern Genie Guides: Nikon D400 (Magic Lantern Guides)” now shown on Amazon.com. And you can pre-order it online now.
This book is written by Simon Stafford, who is a professional writer also written other books, such as: Nikon D800/D800E, Nikon D90, Nikon D7000 and more.
Update: The book at Amazon.com now been removed.