From 2006, two new neutron spectrometers at JET will make it possible to perform advanced Neutron Emission Spectroscopy (NES) diagnosis of most plasmas produced in either Deuterium (D) or mixed Deuterium-Tritium (DT). One of the spectrometers, MPRu, is an upgrade of the Magnetic Proton Recoil (MPR) neutron spectrometer. While providing improved measurements of the 14MeV neutron emission in DT plasmas, the MPRu will also allow diagnosis of the 2.5MeV neutrons in D operations, thereby extending the use of this technique to the full range of fusion relevant energies. In particular, NES diagnosis of JET D plasmas can now be performed with two spectrometers with complementary capabilities and functions.