“… cloud service level agreements must provide for at least 99.95% availability, vendors have to take steps to secure their services, and trouble tickets and order management need to be able to be done via API. Virtual machine services must allow live migration of workloads from one VM to another, while Web hosting services require both Windows and Linux options….”

From InformationWeek article “GSA Outlines U.S. Government’s Cloud Computing Requirements”
http://bit.ly/4nNId