With the advancement of sensor, communication and information technologies, Wide Area Monitoring, Protection and Control (WAMPAC) systems have been identified as the new generation of solutions to improve power system planning, operation, and maintenance. With huge amount of real-time data collected through distributed sensors deployed in a wide area, effective information presentation has become a key component for such systems. Effective information presentation will enable power system operators to be aware of the critical system status, quickly pinpoint the problems, make correct decisions, and take appropriate actions. This paper discusses the requirements of a visualization platform (VP) for a Wide Area Situation Awareness System (WASAS) to be deployed in Southern California Edison Grid Control Center. Major features of such VP, including effective geospatial information presentation, situation awareness with both electrical and non-electrical information, etc., are identified. Corresponding functional requirements are outlined as well. Additionally, this paper discusses the importance of an open VP interface that will be the key for the VP to integrate with many future WAMPAC applications and to be used by other SCE business areas.