I am Amit Sheth, professor of CS at the Univ. of Georgia; Director, LSDIS lab, and
Chief Scientist, Semagix, Inc (and a W3C AC rep). I have been involved in Semantic Web Services/Processes since we advanced the METEOR project (for distributed/adaptive workflow management) to METEOR-S (which adds semantics to
 the entire life cycle for Web Processes) in 2001.
Preliminary ideas related to WSDL-S approach to Web Service/WSDL annotation were presented  in a talk (Semantic Web Process Life cycle: Role of Semantics in Annotation, Discovery, Composition and Orchestration , invited talk at WWW 2003 Workshop on E-Services and the Semantic Web , Budapest, Hungary, May 20, 2003. Abstract Slides: pdf powerpoint-show htm), then documented in Adding Semantics to Web Services Standards , ICWS'03, Las Vegas, Nevada (June 2003) pp.395 - 401.

A white paper "WSDL-S: Adding Semantics to WSDL - White Paper," July 15, 2004) submitted to members of WSDL committee did not get much traction and had some shortcomings.
After significant collaboration with colleagues at IBM (especially Rama Akkiraju and Joel Farrell) and resulting improved specifications, members of LSDIS lab and IBM made a member submission to W3C (Web Service Semantics - WSDL-S), which is now one of the inputs to this activity. WSDL-S page at LSDIS gives further background of the involvement by my colleagues (esp. John Miller), students (esp. Kunal Verma, Meena Nagarajan and  K. Sivashanmugam) and
myself in this area.