Here is another view that I just developed to describe a customer’s level of cloud. I used this view because quite often a public cloud is just regarded as an “outsourced datacenter”, however there are many steps in between the two extremes. Sometimes it’s easier to approach the cloud computing topic from the classical perspective of virtualization.
Anything you would like to add?
I recommend to compare what Amazon, Google or Oracle public cloud offers based on the table above compared to your on premise DC.