Web services have been proposed almost a decade ago as an implementation technology for service oriented architecture. Web service technologies have since been adopted by many users as a vehicle to build such service provision-based software systems. Despite their widespread adoption, Web services still pose significant challenges as well as, opportunities both to the information technology community and, to business community. The challenges deal with engineering, and adoption issues while the opportunities deal mostly with business and operations issues. In this paper, we first discuss the state of the art in the area of Web services, and then we proceed on identifying challenges and opportunities related to designing, implementing, operating and maintaining such systems. Finally, we present emerging technologies that we believe may play a significant role in implementing and deploying the next generation Web services and service oriented systems in general.