I will present a sample of z~2 ULIRGs that we have selected from the Spitzer SWIRE legacy survey, and review follow-up observations of these and other Spitzer-selected z>1 ULIRG samples with VLA, IRS, IRAM and other facilities. I will illustrate predictions for detection of the most luminous ULIRGs in the Universe with the WISE Midex Explorer, launching Nov 2009, and the prospects for detailed study of some of these remarkable objects with the new generation of observatories.