1. A method for managing state data of a service in a service-oriented architecture by establishing a gateway for service-oriented state comprising: configuring an extensible, pluggable interface to support for extensible processor interfaces; data query support on service state data, automated notification capability on service state to a client; and automated data transform on service state data to a client format; defining an interface framework for interaction between a service and said gateway; establishing an extensible meta-data definition comprising an extensible set of service state data attributes including state data qualifiers, constraints, and access mechanisms; and utilizing one or more pluggable processors configured to utilize said extensible meta-data definition for interfaces and decision making based on said meta-data; wherein said extensible data query support on service state data includes: enabling a service developer to define a query type based on a state data schema definition; enabling a service user to send a state data query and query type to said service and transmitting said state data query and query type to a service state query processor; wherein said service state query processor evaluates said query and informs said gateway with state data information to facilitate processing said query and said gateway retrieves said state data information using meta-data information of said service state data; wherein said state data information is converted to a canonical data format to facilitate comprehension by said service query processor; wherein said query processor conducts said query on said service state data; and wherein query results are sent back to said client in a format as requested using a transformation processor.
15. The method of claim 1 wherein said interface framework includes at least one of an interface for managing meta-data associated with said service state data, an interface to facilitate access to gateway functionalities including query execution, semantics and to access a gateway information model, and a plug-in architecture to manage meta-data, query, notification and transform processors.