Recently came across an excellent article around the complexity of cloud here;
If you just use / consume cloud computing the concept seems simple enough, and on the surface it is. However if you are implementing a cloud type service whether a huge public cloud or a smaller private cloud the work involved is considerably more complex.
The cloud concept is to deliver IT services as a utility much like power or other utilities. From a consumer viewpoint this makes the consumption of the services a simple idea. The provision of these services in a reliable, location independent, scalable manner is far from simple. Many larger businesses are either implementing or at least considering the idea of a private cloud, if you are in this camp, or just interested in the complexities of implementing cloud computing then this article makes a great read!