Of course, a printed book can only present information that’s accurate at a certain point in time. C# and .NET won’t change often, but the open standards that enable them will change from time to time, as will the WSE, UDDI Server SDK, and GXA standards, to name but a few. Don’t forget to supplement what you read here with up-to-date information from the MSDN Web services home page (http://msdn.microsoft.com/webservices), GotDotNet (http://www.gotdotnet.com), and other Web service reference sites.