Semantic Web services (SWS) has been a vigorous technology research area for about six years. A great deal of innovative work has been done, and a great deal remains. Several large research initiatives have been producing substantial bodies of technology, which are gradually maturing. SOA vendors are looking seriously at semantic technologies and have made initial commitments to supporting selected approaches. In the world of standards, numerous activities have reflected the strong interest in this work. Perhaps the most visible of these is Sawsdl (Weerawarana, 2005). Sawsdl recently achieved Recommendation status at the World Wide Web Consortium. Sawsdl's completion provides a fitting opportunity to reflect on the state of the art and practice in SWS - past, present, and future. This two-part installment of Trends & Controversies discusses what has been accomplished in SWS, what value SWS can ultimately provide, and where we can go from here to reap these technologies' benefits.