Since early 2000 the JET-EP program has been aiming at optimising JET for ITER-relevant plasma operations, from 2005 onwards. The overall heating capability of JET will be increased to 40MW. The neutral beam system was up-graded but the major technical challenge is to build an ITER-like ICRH antenna, with particularly stringent specifications. The new divertor configuration will be able to absorb more than 300MJ per shot. The physics of the power handling will be monitored by sophisticated new diagnostics, e.g. a high-signal to noise bolometric tomography and an ambitious IR viewing system using a state of the art camera, looking at the antenna and the divertor. New halo sensors will be installed to better understand disruption phenomena. The new divertor's geometry allows high-triangularity ITER-like scenarios with a greater flexibility with respect to different plasma configurations. The control of extreme plasma shapes will be re-enforced and a new disruption mitigation system using a very fast gas valve will be provided. The diagnostic capability will be enhanced by several new systems designed to address a number of crucial physical phenomena for ITER. To study Tritium retention further, new technologically challenging erosion-redeposition diagnostics will be installed, particularly in the divertor region, both real time and integrating. New neutron detectors using the latest advances in scintillators and data recording techniques, detectors for fast _ particles with high pitch angle and energy resolution, high-resolution Thomson Scattering, with 20Hz repetition rate, will provide temperature and density profiles with a spatial accuracy close to two centimeters are the leading items of a much vaster programme. This paper presents an overview of this program, emphasising the main objectives and pointing out the various technological challenges and innovations.