How will cloud computing impact enterprise IT? In answering this question, references to water wheels and modern electric utilities will sometimes come up. This is a useful, though deeply flawed, historical analogy. Don’t think hydro turbines. Think cold-fusion reactors.

I’ll get to that in a moment. First, the waterwheel analogy: This is an idea put forth most famously by Nicholas Carr in his books “Does IT Matter?” and “The Big Switch.”