Mickos makes a great point that cloud is very similar to something that IT shops are currently doing and proving the return on investment of. “There’s a very strong ROI story inherently inside cloud which mimics the one of virtualization.”
He’s of course talking about the notion of taking physical machines that are mostly idle and consolidating them into virtual machines that share the same resources, which always leads to lesser investment of physical resources. He’s also seeing that current cloud customers are mostly in test and piloting mode.
Even if the reality of a specific implementation fails, the model itself — that of elasticity, commodity hardware stitched together by clustering software, economies of scale, shared resources — is compelling enough that it will be successful despite individual implementation failures or successes.
http://www.informationweek.com/blog/main/archives/2010/05/cloud_does_roi.html