Recent numerical and experimental results for freely decaying two-dime
nsional turbulence point to a universal decay in vortex density, rho a
pproximately t(-xi) (xi congruent-to 0.73), from highly turbulent to l
aminar, vortex-free flows. This vortex decay has been successfully des
cribed in terms of a point-vortex dynamics, in close resemblance to th
e vortex dynamics for the two-dimensional Ginzburg-Landau equation. He
re, we add numerical evidence and give theoretical arguments that the
vortex density at late times follows the conjectured power law with xi
= 3/4.