  There are four major X-ray satellites currently in operation, with two more
shortly to follow, and several very ambitious observatories in various stages
of planning. This very rich period of X-ray observation is leading to great
advances in our understanding of the accretion flow onto the black hole,
although we are quickly learning (or perhaps better put, remembering) exactly
how complicated this flow can be. This review was meant to assess future
prospects for X-ray spectroscopy of black hole binaries; however, I first look
backward to the observations and theories that helped us arrive at our current
`paradigm'. I then discuss current and near-future spectroscopic studies, which
increasingly (and very fruitfully) treat X-ray spectroscopy as part of a
larger, intimately connected picture along with radio, optical, and gamma-ray
spectroscopy. Equally importantly, and in large part thanks to the success of
RXTE, there is now a strong realization that spectral-temporal correlations,
even across wavelength bands, are crucial to our understanding of the physics
of these systems. Going forward, we are well-poised to continue to advance our
knowledge via X-ray spectroscopy, both with existing satellites that have a
long lifetime ahead of them, and with the next generation of instruments. If
there is any `hole' in this bright future, it is the potential loss of RXTE,
with no designated follow-up mission. Studies of multi-wavelength
spectral-temporal correlations will become more difficult due to the loss of
two important attributes of RXTE: its fast timing capabilities and its
extremely flexible scheduling which has made many of these studies possible.
