Foundation for further extensions both related to integration with other OMG metamodels like BPDM and BPMN 2.0, as well as SBVR, OSM, ODM and others.
The existing models and meta models (e.g. TOGAF) for describing system architectures turned out to be insufficient to describe SOA in a precise and standardized way. The UML itself seems to be too general for the purpose of describing SOA and needed clarification and standardization of even basic terms like provider, consumer, etc.