On 12-February-2012, the NSF (National Science Foundation) released a report on cloud computing research. The NSF calls cloud computing a vital area in which to continue research investments. Among the topics highlighted by NSF:
From an architecture perspective, the report mentions Nebula. "The NEBULA architecture achieves the three security properties of confidentiality, integrity and availability using a system approach." This approach is supported by my dissertation research using the systems approach to design confidentiality and integrity into cloud based systems, specifically with respect to data privacy, authentication, and authorization.
The entire NSF report is available here: http://www.nsf.gov/pubs/2012/nsf12040/nsf12040.pdf