Actually I also wonder how samples are working, but when I copied all samples source files into Eclipse with Maven plugin, it couldn't find this class.
I deployed JBoss WS 3.0.5 native to my Jboss Portal 2.6.3 (On JBoss 4.2.2) and all tests except one (GenerateProject) passed (see attached results).
I copied test classes to Eclipse to learn how they work. Now it showing missing class import org.jboss.ejb3.client.ClientLauncher in the following test:
org.jboss.test.ws.jaxws.samples.webserviceref.ebServiceRefClientTestCase which is probably should test plain java client but not EJB3 one...