For years I have argued that SOA is all about asynchronicity. SOA is all about temporal decoupling. Distributed Transactions is for the birds in the general case etc.etc.
In the last, say, 2 years, I have backed away almost completely from the whole SOA thing because my notions of what an SOA is have not been shared by the majority-holding corba/rpc-with-angle-brackets exponents.
It is refreshing to hear Pat Helland explain what he conceptualises as SOA. He is saying what I have been thinking, but he us doing it with much more authority and much better analogies that I could ever muster.
Way to go Pat Helland.
Maybe the SOA acronym is recoverable after all?