This paper presents a novel evaluation study of the Cloud Computing technology, with a focused emphasis on the Cloud Storage mechanisms and the way they are affecting the progress of the present Cloud Services. Considering the exponential growth of the user data and its impact on the Cloud Storage infrastructure, this work provides two major contributions through comprehensive performance evaluations. Firstly, it proposes a unique 10-point performance evaluation framework for existing Cloud Storage infrastructure and applies it for evaluating six major Cloud Storage Service Providers currently in the market. Secondly, it presents a detailed insightful assessment of eighteen most popular Cloud Storage Hardware vendors with respect to the storage technologies being implemented by them. In conclusion, it takes stock of the current trends on optimizing storage infrastructure for Cloud Computing and predicting future research possibilities in this rapidly growing technology.