Erik Johnson suggested that I make the distinction between big SOA and little SOA.

I think this is a very good way to distinguish the big-bang, 'mega' approaches - afflicted by what I call the build-it-and-they-will-come syndrome - which suffer from too much planning, dare I say too much architecture,  and far too little business value - call this big SOA. Big SOA is often plagued by enterprise-wide-itis and has a tendency to become a consulting exercise.

Little SO on the other hand is all about agility - about addressing clear business challenges and creating business value. It is often driven in a middle-out manner. The focus here is not on creating an 'SOA' but on using architecture principles and patterns to design and build loosely-coupled services and applications towards addressing a business challenge or exploiting a business opportunity.

As you can see, I am a big fan of Little SO.