Although Event Stream Processing (ESP) systems exit for already more than a decade, we recently witness a true renaisance for ESP systems that have adopted the popular MapReduce paradigm. In this white paper, we advocate for the StreamMapReduce approach as it allows a (i) quick and easy transition of legacy MapReduce-based applications to ESP, (ii) simplifies the implementation of fault tolerance mechanisms, and (iii) elasticity in order to operate in nowadays cloud environments. We will furthermore showcase two real world applications from the area of SmartGrids and geo-spatial data stream analysis where the StreamMapReduce approach has been successfully applied.