The gain in sensitivity, band width and spatial resolution achieved by NOEMA and ALMA will allow deep studies of the structure and chemistry of the interstellar medium, across the Milky Way galaxy as well as in nearby galaxies. In this talk I will discuss the new vision of the ISM brought by the Planck and Herschel results and the open issues that need further studies at high spatial resolution. I will show how the need for accurate chemical modeling requires new advances in molecular physics and which steps are now taken to make progresses.