A better idea would be for a kernel book to be written by more than one person. Robert Love doesn't scale any more than Linus does. The "best" strategy would be for people deeply involved to develop basic knowledge dumps/draft chapters in their area of specialty, with an overarching author (Robert Love, for example) to unify the style, formatting and content to produce a coherent story from the fragments.
Also, I'd suggest moving from the monolithic book concept to a framework where each chapter is on a rail of some kind and can be slid out and replaced. The book will then never be "out-of-date" and the upgrades can all be sold in such a manner that it makes the publisher just that little bit richer.