The agent paradigm, with its new way of thinking about software systems as a collection of autonomous, flexible and robust agents, offers a promising solution for modelling and implementing distributed complex systems. Intelligent agents and services share a substantial number of key concepts such as autonomy, reactivity, loose coupling and strong encapsulation. There has been, however, little work on leveraging such a deep connection between agents and services. In this paper, we argue that agent-oriented software engineering (AOSE) provides an important basis for service analysis and design at the business service level. In particular, we show how concepts and techniques in AOSE can be used to analyse and model business services in the context of service ecosystems.