In October 2011, the U.S. Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy (EERE) and Office of Electricity Delivery and Energy Reliability (OE), hosted a two-day workshop in Washington, DC to examine technical, institutional, economic, regulatory, and policy issues regarding the participation of load as a provider of ancillary services (AS). The purpose of the workshop was to inform DOE's research priorities on grid reliability needs in the context of today's power system and possible future systems with high penetrations of variable generation. Drawing from the workshop presentations and discussions, this paper summarizes the perspectives of the workshop attendees on the state of progress, issues, barriers, and potential for load participation in ancillary services.