One of the tenants of Service Orientation is that the boundaries are explicit. Boundaries are usually expressed in the form of the data that is passed back and forth, but I challenge all designers to exceed that simple level of understanding and to make sure that the real boundary is one of responsibility, not data. Make a service responsible for all cohesive methods that fulfill a single responsibility that can be expressed for the business.
Yep… Responsibility Oriented Partitioning is alive and well in the SOA world.