RJ Lipton, who has been one of the primary communicators/bloggers of the recent P vs. NP happenings, and someone with a long-time particular interest in the issue, has newly published a book on the topic, "The P = NP Question and Gödel’s Lost Letter":
(it's a tad expensive, and NOT bedtime reading!)
What ought make the book particularly interesting though is that Lipton is among the minority who still believe that P may indeed EQUAL NP (versus the majority belief that P ≠ NP).
Changing gears from one deep problem to another, Harvard mathematician and Fields Medalist Shing-Tung Yau has a recent well-received book out, "The Shape of Inner Space," which recounts the geometry/mathematics underlying string theory:
ADDENDUM: Peter Woit's review of Yau's book is now up here: