Here’s their description of the paper:
Version 3 of the White Paper addresses the importance of Security in the Cloud. Security in the Cloud is consistently raising the most questions as consumers look to move their data and applications to the cloud. Cloud computing does not introduce any new security issues; the issues that apply to cloud-based solutions are the same issues that apply to in-house solutions. The discussion of security in the paper covers the security controls and federation patterns that cloud providers must deliver.
The paper provides a good overview of cloud computing and provides a taxonomy that is useful for having a discussion of cloud computing. There’s also a pretty active Google Group for discussing cloud computing use cases and discussion of the paper worth watching as well.