  The causal entropic principle aims to predict the unexpectedly small value of
the cosmological constant Lambda using a weighting by entropy increase on
causal diamonds. The original work assumed a purely isotropic and homogeneous
cosmology. But even the level of inhomogeneity observed in our universe forces
reconsideration of certain arguments about entropy production. In particular,
we must consider an ensemble of causal diamonds associated with one cosmology,
and we can no longer immediately discard entropy production in the far future
of the universe. Depending on our choices for a probability measure and our
treatment of black hole evaporation, the prediction for Lambda may be left
intact or dramatically altered.
