Cloud computing is an unavoidable future of IT. Actually the future of cloud computing is still a little bit cloudy but quickly converging in a stable and reliable form. Big players gonna dictate the pace and the degree of freedom, security and privacy.
Anyway, I am slowly moving in one of those clouds hoping that they unify and synergetically combine all concepts. Actually after some time I use for testing purposes 3 different. You ought to feel comfortable being publicly naked and then everything is OK!