Recent advances in superconducting technology have enabled dramatic improvements in the sensitivity of millimeter and sub-millimeter wavelength instruments in the last decade and helped to usher in the era of precision cosmology. The next frontier is intensity mapping: using large arrays of spectrometers to build a 3D model of the emission from galaxies, with the ability to measure the star formation history throughout the epoch of reionization and to significantly constrain extensions to contemporary cosmology and inflation. The key to this technology are superconducting detectors and the microwave readout required to populate dense focal planes. In particular, kinetic inductance detectors (KIDS), high-frequency band defining features, and multiplexed readout of thousands of background-limited channels on a single microwave line will play a key role in future experiments. I'll discuss several near-future instruments that will deploy this technology and the prospect for future instruments that will provide unique information about both astrophysics and fundamental physics.