Following my previous post on Grandpa's SOA, JJ responded with another post on SOA misconceptions. I think we are broadly in agreement - SOA may have some traces in the past, but industrial-strength SOA was not possible thirty years ago.
JJ also criticizes the notion that services are like LegoTM. This analogy has been overused since the early days of component-based software engineering, and it has just enough plausibility to survive as a vague approximation, but as JJ points out it leads (as analogies often do) to gross simplifications and misconceptions.
Similar to the belief that smart kids can build enterprise solutions using Ajax and Google Maps. Again, there may be a few exceptional examples of this, but it is not a sufficiently sound basis for industrial-strength SOA.