From SOA is a Business-Driven Architectural Style:
"It means that for SOA to be successful, it must be a 'top-down' approach. And top-down, means problem to architecture to solution. It does not mean, working from what we have and just wrapping it with new technologies just because we can. This bottom-up approach is quite natural and easy and is the perfect recipe for a SOA failure. "
I will go a bit further and say that any architecture that isn't bent on solving a particular problem is a recipe for failure.
