In a recent conference, analyst William Forrest says that large companies could end up paying more than twice as much by using cloud based services. According to a Forbes.com report, Deflating The Cloud, a study focused on a McKinsey & Co. financial services client showed that the financial firm would be paying 150% more for cloud-based services versus owning the infrastructure.

"Much of cloud computing's misplaced hype, contends Forrest, comes from the assumption that businesses that make the switch will be able to do away with their entire IT department, an expensive collection of personnel. But in his analysis of McKinsey's financial services client, Forrest found that only around 15% of the company's 1,700 or so IT employees had hands-on access to hardware and software--most worked in support or other administrative areas. That means moving to Amazon's service would only cut about 200 full-time workers, hardly the savings chief information officers might imagine."

Others, including Amy Wohl leading analyst at Wohl Associates, disagree arguing that Forrest's analysis leaves out the value of avoiding large capital outlays and ignores the flexibility inherent in cloud computing.

This is actually a good debate. The economic value of cloud computing needs to be studied carefully. Cloud computing is not the answer to all IT ills and if this market is to be successful, both the pros and cons must be well understood.