Maybe I have chosen the wrong topic but I am genuinely mystified by Service Oriented Architecture. I have just read two books on the subject and yet another essay and I still don't understand it.

First, is this an example of a label that sounds seriously impressive but is totally meaningless?

Second, are the concepts contained within SOA just an aggregation of all the things we have been doing - or should have been doing? For example: customer focus, scope, terms of reference, objective breakdown, requirements definition, technology as an enabler, flexibility, collaboration. Yet SOA is billed as a new approach and the most significant technology initiative today.

Third, let the Big Boys use their marketing muscle and create whole divisions of consultants, supported by beguiling adverts. And lo! everyone thinks it's a brilliant idea and the Big Boys make a lot of money. Many people are susceptible to anything that promises salvation that they fail to use their critical thinking ability.

So, I am still asking:

What is SOA?
How is it unique?
What are the benefits?

Can anyone answer these three questions with no more than twenty words on each one?