The Herschel Space Observatory is a major astronomical facility
currently scheduled for launch in September 2008. It comprises at
3.5m telescope cooled to ~70K, and three instruments which operate
in the wavelength range between 60 ${\mu}$m and 670 ${\mu}$m.
Herschel will be the first observatory offering essentially
continuous spectra coverage throughout the submm/FIR region of the
spectrum via three focal plane instruments, PACS, SPIRE, and HIFI.
All of these operate as spectrometers, with f/${\Delta}$f between a
few hundred and a few million. Herschel includes imaging photometric
capability throughout this broad range. The wavelength coverage,
sensitivity, and spectral and angular resolution of Herschel offer
enormous new capability for many areas of astronomy, ranging from study
of star-forming cloud cores to high redshift galaxies.
Spectroscopy of molecular lines and atomic fine structure transitions
will give new insights into processes in regions including molecular
clouds, protostellar and debris disks, photon dominated regions, and
active galactic nuclei. In this talk I will review Herschel
performance, highlight some of the astronomy proposed in Guaranteed
Time Observations, and summarize current status and opportunities for
theoretical and observing proposals and associated funding.