Do you have an SOA strategy and vision? What is your concept of services? Is appropriate SOA governance in place?
When I evaluate the SOA maturity of organizations, I like to examine the following criteria: SOA strategy and vision; services concept and maturity; SOA architecture and technology stack; SOA governance and policy enforcement; organization and culture; and SOA metrics and results to date.
These dimensions frame how well an organization has prepared itself for SOA success. How ready are you for SOA? A simple self evaluation on these maturity dimensions will give you a better feel for your readiness. Most importantly, it will help ensure you've considered these important aspects of SOA.