Before reading "Web Services Security" (WSS), my knowledge of Web Services relied on a few magazine articles and chapter 10 of "Hacking Exposed: Web Applications." After reading WSS, I have a better idea of how Web Services work and how a variety of acronyms (XACML, XKMS, SAML, etc.) provide security. This 312 page book isn't lengthy enough to make you a Web Services security expert, but it provides a good foundation for consultants and other professionals.
The latest SANS NewsBites mentioned a story where TriWest Healthcare is being sued for losing customer data to an intruder.