  We argue that the thermodynamics of conformal field theories with AdS duals
exhibits a remarkable universality. At strong coupling, a Cardy-Verlinde
entropy formula holds even when R-charges or bulk supergravity scalars are
turned on. In such a setting, the Casimir entropy can be identified with a
generalized C-function that changes monotonically with temperature as well as
when non-trivial bulk scalar fields are introduced. We generalize the
Cardy-Verlinde formula to cases where no subextensive part of the energy is
present and further observe that such a formula is valid for the N=4 super
Yang-Mills theory in D=4 even at weak coupling. Finally we show that a
generalized Cardy-Verlinde formula holds for asymptotically flat black holes in
any dimension.
