I really enjoyed reading this article about Zynga IT's approach to cloud because of it's stark contrast to Intel IT's approach. While the approaches for each IT organization were different, what stood out to me is the similarities in what drove the two approaches. Both approaches were developed with the business needs in mind. In both examples the business requirements drove different technical cloud implementations and strategies utilizing hybrid clouds (a mix of public and private cloud based solutions).
At Zynga, they concluded an "outside in" approach was best - launch new services in public cloud and migrate them internal as business demand stabilizes.
While at Intel IT, we determined an "inside out" strategy was best - focusing first on building a private cloud to gain cost efficiencies and businss agility while improving availability and maintaining information security - and then looking to public cloud to support non-differentiated services today and support cloud bursting use cases for highly variable workloads tomorrow.
I'm interested in hearing about other IT approaches .. just post the links below in the comments