The more you focus on the business benefits of Cloud, the more likely you’ll be leaning toward public over private deployment models. Furthermore, this mind shift isn’t all about security risks. Once you work through the issues, you’ll likely come to the same conclusion: there’s generally little or no solid business reason to build a private Cloud.
Perhaps the most interesting contrast between the perspectives of these two audiences was their respective opinions about private Clouds. The techies at the Bangalore conference, having drunk too much of the vendor Kool-Aid, were generally of the opinion that public Clouds were too risky, and that their organizations should thus focus their efforts on the private deployment model. The Dallas business crowd, in contrast, generally held that the public approach was the way to go, with some folks even going so far as to claim that public Cloud was the only true approach to Cloud Computing.
So, should any organization build a private Cloud? Perhaps, but only the very largest enterprises, and only when those organizations can figure out how to get most or all of their divisions to share those private Clouds. If your enterprise is large enough to achieve similar economies of scale to the public providers, then—and only then—will a private option be a viable business alternative.