The first release date was March 2005. Since then it has been delayed every 3-6 months. Therefore any stated release date has lost any credibility at this point. See: any good study guide for SCDJWS?. It is not clear for how long the guide can remain current as the SCDJWS is based the J2EE 1.4 Web service standards and JAX-WS 2.0 is finding wider acceptance as time passes.
Will Sun be updating the SCDJWS anytime soon? Nobody knows. The more popular certifications (SCJP,SCWCD,SCBCD) are updated first and more often. The SCEA hasn�t been updated since 2000 (Part 1 is still based on EJB 1.0; the SCBCD has been recently updated to EJB 3.0). If you compare the traffic in those forums to the SCDJWS forum you will realize that the SCDJWS isn�t that popular.
If you decide to wait for an updated version of the SCDJWS you need to realize that you may be waiting for a long, long time (maybe 24 months, possibly longer); there is no guarantee that preparation materials will be any better then.