Cloud computing is an emerging paradigm that allows adoption of on-demand services in a cost-effective way. Migrating services to the Cloud also means been exposed to new threats and vulnerabilities, thus, resulting in a modified assessment of risk. Assessing risk in the Cloud remains an open research issue, as it requires a given level of trust of the Cloud service provider for providing assessment data and implementing controls. This paper surveys existing knowledge, regarding risk assessment for the Cloud, and highlights the requirements for the design of a cloud-targeted method that is offered as a service, which is also in compliance with the specific characteristics of the Cloud.