Those guys over at Oracle have just published a white paper on Architectural Strategies for Cloud Computing:
"For IT departments in larger enterprises, developing a private cloud often makes the most financial and business sense. When developing the architectural vision, an enterprise architect should bear in mind the characteristics of cloud computing as well as consider some of the organizational and cultural issues that might become obstacles to the adoption of the future state
To read the entire article at its source, please refer to Whitepaper: Architectural Strategies for Cloud Computing