The James Webb Space Telescope has just passed two huge milestones; completion of: 1.) the telescope itself; and 2.) its entire instrument package. The project has held schedule (and budget) since being replanned in 2011 and is heading toward launch in October, 2018. Although there are many more steps to take before then, most notably a full system test in the mid-2017, it is urgent to plan how to use our new flagship space telescope. The guaranteed time observational programs will have been defined, an Early Release Science program will allocate 500 hours roughly in July, 2017, and the call for General Observer proposals will be released in November 2017. This talk will focus on the capabilities of the observatory, emphasizing the advances over present (and even some future) facilities, with examples of the science it will enable. JWST will redefine our views of topics ranging from exoplanets to the first galaxies and super-massive black holes.