After quickly reviewing the existing evidence for neutrino oscillations, I
summarise the goals and capabilities of the JHF-Kamioka long baseline superbeam
experiment. Theoretical implications of what this experiment could potentially
discover are then discussed.Comment: 10 pages, 3 figures, LaTeX, ws-procs9x6.cls. Invited talk at the
Workshop on Physics at the Japan Hadron Facility (JHF), Adelaide, 14-21 March
200