  We introduce a "microcanonical" measure (complying with the "general
canonical principle") over the second moments of pure bosonic Gaussian states
under an energy constraint. We determine the average fidelity for the
teleportation of states distributed according to such a measure and compare it
to a threshold obtained from a feasible classical strategy. Furthermore, we
show that, under the proposed measure, the distribution of the entanglement
concentrates around a finite value at the thermodynamical limit and, in
general, the typical entanglement of Gaussian states with maximal energy E is
not close to the maximum allowed by E.
