Hot off the press: there's a new whitepaper entitled, What Is Real-Time SOA? available on RTI’s website.
This paper asks (and answers!) the question, "How should a real-time SOA be implemented? "Does real-time SOA simply entail faster Web services or a faster Enterprise Service Bus (ESB)? Or, do real-time systems require different technologies? This topic is becoming increasingly important as real-time systems scale up and are integrated into Systems of Systems. Without the right underlying architecture and technology, systems could fail to meet their performance requirements and integration costs could explode.
You can download the white paper from here.