The great paradigm shift of cloud computing is not self-service...

This is the best article on real cloud benefits I have read this year.

There has been significant discussion over the short life of the term "cloud computing" about how little it differs from concepts like managed hosting and ASPs. And there is some truth to these observations; if you really look closely, what are the key differences between EC2 and a more traditional managed hosting provider? Some would say multi-tenancy, self-service and pay-per-use (including billing and elastic capacity). With specific regard to EC2, I would tend to agree.

(I would also hasten to point out that Amazon provides some very PaaS-like services in conjunction with EC2, such as Simple Queuing Service (SQS) and SimpleDB.)

CNet article