I’ve spoken with quite a few analysts and students who are concerned about cloud security. I have some serious reservations myself, but there are in fact some good resources on developing secure configurations for clouds, networks and servers. A very good one, courtesy of SubnetD (who provides the Twitter feed you see to the right on my home page), is the Center for Internet Security, which provides baseline configurations specs in a series of valuable PDF publications.
See http://www.cisecurity.org/. Aside from the benchmark configuration documents, they also run a cyber-threat info sharing center, and a Cybersecurity Workforce Development operation. If you’re interested in cyber security, or looking for work in the field, this site is a must-know.