"I wrote the book in collaboration with Google" Chances are that he's not the sole author/owner of the copyright of the book. It's possible that other features

"I wrote the book in collaboration with Google" Chances are that he's not the sole author/owner of the copyright of the book. It's possible that other features of G+ that haven't been released yet are in the book, and that Google is waiting for a full launch..? That's my best guess.