The development for ITER of integrated operating scenarios with acceptable first wall power loadings and high fusion power has gained urgency in view of JET's intent to install an ITER-like beryllium wall, tungsten divertor and major heating system upgrades. Since the last IAEA Conference the understanding of key issues has progressed with recent analyses of past results and the first results from the 2006 Experimental Campaigns, which exploit new enhancements, extending operation to highly shaped, high power plasmas with an improved diagnostic capability. Issues related to the core plasma performance include global energy confinement, temperature profile stiffness, toroidal momentum transport, density peaking, impurity accumulation, core MHD and fast ion effects. Active control of the local current profile is seen as a means to improve performance by modifying MHD and transport effects. Issues related to the edge plasma include the erosion of plasma facing components caused by high power loadings that result from edge MHD instabilities which must be ameliorated, and edge material migration which can influence fuel retention and inventory. The need to resolve these issues re-enforces the need to test ITER wall materials under high performance conditions, as foreseen in the longer-term JET programme in support of ITER.