  A significant population of distant sub-millimeter-selected galaxies (SMGs)
with powerful dust continuum emission that matches the luminosity of the
brightest QSOs and exceeds that of most extreme local galaxies detected by
IRAS, has been known for almost a decade. The full range of powerful ground-
and space-based facilities have been used to investigate them, and a good deal
of information about their properties has been gathered. This meeting addresses
some of the key questions for better understanding their properties. While
continuum detection is relatively efficient, a spectrum is always required both
to determine a distance/luminosity, and to probe astrophysics: excitation
conditions, the total mass, the mass distribution and degree of dynamical
relaxation. Once a redshift is known, then the associated stellar mass can be
found, and more specialized spectrographs can be used to search for specific
line diagnostics. The first generation of submm surveys, have yielded a
combined sample of several hundred SMGs. Here we discuss the size and follow-up
of future SMG samples that will be compiled in much larger numbers by
JCMT-SCUBA2, Herschel, Planck, LMT, ALMA, and a future large-aperture
(25-m-class) submm/far-IR wide-field ground-based telescope CCAT, planned to
operate at a Chilean site even better than ALMA's. The issues concerning
placing SMGs in the context of their environments and other populations of
high-redshift galaxies are discussed.
