Just like Design Patterns, Enterprise Integration Patterns and Architecture Patterns, Thomas Erl comes with a SOA Design Pattern book.
InfoQ has an interview with him: read interview
He states that a SOA patterns is something different than a webservice patterns. SOA is about services and a webservice is a technology specific realization of a service. He also states that in fact EAI frameworks and middleware, enterprise service bus platforms, grid computing, transaction management systems, messaging queues, event-driven messaging frameworks, broker and mediation technologies were used as inspiration for the SOA patterns.
He also explains his difference between service orientation and a SOA: "Service-orientation is a distinct paradigm that you apply to achieve a specific target state and a technology architecture is considered service-oriented if it has the characteristics necessary to support the application of this paradigm." Nice and clear right?
I have not read the book (yet), but I will come back to it. Hopefully it helps to answer when a service is a service. Does it have to have business value, or can secondary business functionality like HRM services also be considered services?