Some reassuring words from Amazon's Werner Vogels:
We went through a period of serious introspection and concluded that a service-oriented architecture would give us the level of isolation that would allow us to build many software components rapidly and independently. By the way, this was way before service-oriented was a buzzword. For us service orientation means encapsulating the data with the business logic that operates on the data, with the only access through a published service interface. No direct database access is allowed from outside the service, and there's no data sharing among the services.
Over time, this grew into hundreds of services and a number of application servers that aggregate the information from the services. The application that renders the Amazon.com Web pages is one such application server, but so are the applications that serve the Web-services interface, the customer service application, the seller interface, and the many third-party Web sites that run on our platform.
If you hit the Amazon.com gateway page, the application calls more than 100 services to collect data and construct the page for you.
Yeah, I like all that. But I want it bigger and I want anyone to be able to do it :-)
(via Dan Creswell)