The Astro2010 Decadal Survey gave its highest recommendation in the large-scale space mission category to WFIRST, a Wide-Field Infrared Survey Telescope with both imaging and spectroscopy capabilities. The science made possible by such a facility reaches across many disciplines from dark energy to exoplanets to deep surveys. The proposed mission will conduct microlensing observations of stars in the galactic bulge, near-IR surveys of thousands of square degrees to magnitudes limits of AB ~25, spectroscopic measurements of a hundred million galaxies to redshift accuracy of ~0.1% and precision supernova observations into the near-IR of thousands of events. It will be a powerful tool for the astronomical community. The purpose of this workshop is to inform the community of the planned capabilities and gather input for defining the mission and its science.