Those who think cloud computing requires no forethought or planning are dead wrong. Considering the fact that cloud computing is a truly complex distributed architecture, there is a lot to think about in terms of what components are leveraged (e.g., storage, compute, database, etc.), how they are configured, governance and security, and monitoring and management. Just to scratch the surface.
Thus, those who implement cloud computing need to get smart around how to approach the architecture. Many skip this step or role and move directly to the good stuff, the technology. A lack of planning and architecture will absolutely derail your cloud implementations, short- and long-term.