Joseph Cartman and Richard Ting provide a sweeping overview of mobile design, from describing the interaction design process (2-3 pages) and usability testing (2 pages) to typography (4 pages) and different methods of communications (22 pages.) The book is an easy read, with each section providing strategic implications and occasional topics dipping far deeper.
If you are interested in thinking from a strategic perspective about taking your organization mobile, this book is very good. But anybody who must work on actual pixels or lines of code or even dollars will need much more, on every topic.
The best part of the book for the experienced designer is the small case studies in the last chapters.