I have been a strong advocate of the notion of service eco-systems and have been sharing patterns that help accomplish this task through the design of SOA and SOI that is conductive to the creation and maintenance of a stable service eco-system.
Others have been talking aout various aspects of a service eco-system as well. For example, The role of contracts in the service ecosystem . Some talk about the Web Services Eco-system and how we need tools for consumpiton, test, creation and management.
Recently, George Galambos of IBM delivered a keynote on the Service Eco-system at the IEEE Int'l Conference on Web Services 2005.
Aside from wildlife foundations, Economists also have found interest in ecosystems. For example, they discuss the valuation of an ecosystem .
We'll be hearing much more about this important concept as technologies and organizations mature in their usage and adoption of SOA.