We are working on second edition of PostGIS in Action 2ed for availability sometime in late 2013/early 2014. Early purchase review (MEAP) is now available for Second Edition. With MEAP you can get chapter updates as we write them and get the final polished copy at release time.
Our most recent book
PostgreSQL: Up and Running is out in both E-book and hard-copy. You can order hard-copy now from Amazon or Kindle
or hard-copy or e-Book from O'Reilly .