This presentation will discuss cloud computing from the evolution of service orientation point of view. It will discuss cloud computing models, the prior-arts, and the evolution path in federal government from Federal Enterprise Architecture, Service Oriented Architecture (SOA), and Service Oriented Infrastructure (SOI) or Federal Infrastructure Optimization Initiative, to Cloud Computing. It will also discuss the current trend of the new generation IT operating model, as well as the related business impact. While cloud computing is contributing to the enterprise evolution towards service orientation and shared services, appropriate business management and operation mechanisms must be in place in order to practice successfully, e.g. suitable business models, service models, service structure, funding models, operation models, operation structure, as well as lifecycle and governance. This presentation intends to provide a holistic view for the cloud computing evolution and shared service adoption in Federal Government.