The notion of a service-oriented architecture is real, and it can deliver. The term "SOA", however, has been entirely hijacked by a band of dangerous Taj Mahal architects. They seem innocuous, it part because they’ll lull you to sleep with endless protocol diagrams. Behind the soporific technology discussion lies a grave threat to your business.
"SOA" has come to mean top-down, up-front, strong-governance, all-or-nothing process (moving at glacial speed) implemented by an ill-conceived stack of technologies. SOAP is not the problem. WSDL is not the problem. Even BPEL is not the problem. The problem begins with the entire world view.
We need to abandon the term "SOA" and invent a new one. "SOA" is chasing a false goal. The idea that services will be so strongly defined that no integration point will ever break is unachievable. Moreover, it’s optimizing for the wrong thing. Most business today are not safety-critical. Instead, they are highly competitive.
We need loosely-coupled services, not orchestration.
We need services that emerge from the business units they serve, not an IT governance panel.
We need services to change as rapidly as the business itself changes, not after a chartering, funding, and governance cycle.
Instead of trying to build an antiseptic, clockwork enterprise, we need to embrace the messy, chaotic, Darwinian nature of business. We should be enabling rapid experimentation, quick rollout of "barely sufficient" systems, and fast feedback. We need to enable emergence, not stifle it.
Anything that slows down that cycle of experimentation and adjustment puts your business on the same evolutionary path as the Great Auk. I never thought I’d find myself quoting Tom Peters in a tech blog, but the key really is to "Test fast, fail fast, adjust fast."