An excellent article on integrating the Policy Injection Application Block with WCF Services : http://msdn.microsoft.com/msdnmag/issues/08/02/PIABWCFBehaviors/default.aspx

Another article on What's New for WCF in Visual Studio 2008: http://msdn.microsoft.com/msdnmag/issues/08/02/Foundations/default.aspx