The Software Project Manager's Bridge to Agility - Michele Sliger and Stacia Broderick
Co-authors Michele Sliger and Stacia Broderick do a great job of making agility more accessible to traditionally trained project managers. Both PMPs and CSTs, Michele and Stacia have solid roots in both the traditional and agile worlds that serve as the foundation of this work.
They ably provide great review of the nine PMBOK® knowledge areas and how they correlate to agile processes. Both traditionalists and agilists might be surprised by the significant commonality there really is bewteen these two worlds. While some in the agile community might say "so what", I think the effort to engage traditional project managers can only advance the adoption of agility.