  If the dark energy equation of state is anisotropic, the expansion rate of
the universe becomes direction-dependent at late times. We show that such
models are not only cosmologically viable but that they could explain some of
the observed anomalies in the CMB, and shed some light into the coincidence
problem. The possible anisotropy can then be constrained by studying its
effects on the luminosity distance-redshift relation inferred from several
observations. A vector field action for dark energy is also presented as an
example of such possibility.
