Web services are a big field, so it is an overstatement to say that "Java 6 includes WS" (which are an architectural and implementation approach, not a particular piece of software).
Java 6 does include the JAX-WS API, which is one of the APIs commonly used to implement WS; that's just a small part of WS, though. The
http://faq.javaranch.com/java/WebServicesFaq links to a couple of articles explaining how to use JAX-WS with Java 6 in the "How do I get started building a web service?" section.
[ May 20, 2008: Message edited by: Ulf Dittmer ]