  We discuss several opportunities involving cosmic microwave background (CMB)
observations during the post-MAP era. The curl-modes of CMB polarization allow
a direct detection of inflationary gravitational waves and a measurement of the
energy scale of inflation. While a significant source of confusion is expected
from cosmic shear conversion of polarization related to density perturbations,
higher resolution observations of CMB anisotropies can be used for a lensing
reconstruction and to separate gravitational-wave polarization signature from
that of lensing. With perfect all-sky maps, separations based on current
lensing reconstruction techniques allow the possibility to probe inflationary
energy scales down to 10^15 GeV, well below that of grand unified theories.
Another aspect of future CMB studies will be related to large scale structure,
such as wide-field imaging of Sunyaev-Zel'dovich (SZ) effect in galaxy
clusters. Here, we comment on a potentially interesting and unique application
of the SZ effect involving a measurement of the absolute temperature of CMB at
high redshifts. Finally, we address cluster polarization signals and the
possibility to directly measure some aspect of the temperature quadrupole
associated with time evolving potentials.
