SOA from a vendor perspective is whatever tool they are selling in the space: ESB, Design Time Governance, Runtime Governance, Policy Management, Registry & Repository, etc. What they always sell is the tool, never the process.
Since the A in SOA is Architecture, and the true value of SOA is SOA for the Enterprise (as opposed to SOA for Integration), it takes implementation of a SOA architecture pattern to get the hyped SOA benefits. But as noted above, this is not what vendors are selling.
As most organizations focus on SOA for Integration and layer on a few tools rather than applying architecture and an organizational change process (which, face it, is hard), only incremental benefits will be gained. This is not a surprise, IT managers are rarely rewarded for shaking things up and taking risks.
Much of SOA is about creating, managing, motivating organization changes - the process of which is not unique to SOA but SOA for the Enterprise is completely dependent upon.