I agree that alternate sourcing is enabled through virtualization. Initially mapping some virtualized resource (machine, application, application component etc.) onto the physical resources required to support it will occur within the IT department or datacenter. However, federating local infrastructure (a private cloud) with external infrastructure (public clouds) opens up the possibility of competition between public clouds with regard to all aspects of service delivery. Indeed the private cloud will be itself in direct competition with the public clouds and, as public clouds improve their service and reduce their costs, those clouds could eventually replace much, if not all, of the local infrastructure. Here at Arjuna we think this form of arbitrage between clouds will be of great benefit to business but that delivering on this vision requires the ability to dynamically create and maintain effective service agreements between federated clouds. Our product, Agility, attempts to address these issues.