I'd argue this (performance/cost) is exactly the right metric to measure. One of the biggest benefits of the cloud is elasticity. In on-premise world, one would have to provision based on peak demand, and most of the time the cluster utilization rate is pretty low.

But it's cost for every iteration for cloud vs a once off cost for on premise. It doesn't take very long for on premise to get cheaper.

The one-off cost is very high, and there is higher ongoing maintenance cost as well. Most organizations are moving to the cloud, because it in general makes more economic sense.

I'm really not seeing most organizations moving to the cloud. It only makes sense economically for the smallest companies/organisations that can't afford maintenance costs. Most bigger ones won't risk the loss of their core data and a lot can't go to the cloud for various reasons like legality, speed and redundancy.

Take a look at the customers featured at reinvent. Computing as "utility" is the future, and the future is arriving fast.