The Cloud Security Alliance is a group formed to promote best practices in the provision of assurance in the cloud environment. their guidance has achieved a good deal of respectability in its brief life.
Recently, the CSA launched an initiative to find volunteers to update its initial guidance. To help potential volunteers, it released the CSA Cloud controls Matrix, which can be downloaded from its website.
Assurance in the cloud has become a major field and is one where the best of standards are needed. The CSA is one of several sets of guidance being offered for cloud security purposes. Others include ISO 27001/27002, ISACA COBIT, PCI, NIST and the AICPA's new SOC 1 and 2. Hopefully, better security in the cloud will emerge from all this effort.