One justification for including JAX-WS 2.0 as part of Java SE 6.0 instead of Java EE 5 is that web service delivery with JAX-WS 2.0 does not require a servlet or EJB container.
The Abstract WSDL documents business-specific information. The Concrete WSDL however is technical in nature and may have nothing to do with business-specific information.
WSDL-based Web Services define a stateless model and an unordered set of operations. WSDL and therefore WSDL-based web services do not have the concept of state ...
When exposing a service interface to external clients, always expose Request/Response Message Exchange Patterns (MEPs) as much as possible since they work best with HTTP transports and provide interoperability.