  Starting from a nonperturbative expression for entropy and density obtained
from $\Phi$-derivable two-loop approximations to the thermodynamic potential, a
quasiparticle model for the thermodynamics of QCD can be developed which
incorporates the physics of hard thermal loops and leads to a reorganization of
the otherwise ill-behaved thermal perturbation theory through order
$\alpha_s^{3/2}$. Some details of this reorganization are discussed and the
differences to simpler quasiparticle models highlighted. A comparison with
available lattice data shows remarkable agreement down to temperatures of $\sim
2.5 T_c$.
