  The magnetization of a ferromagnet (F) driven out of equilibrium injects pure
spin current into an adjacent conductor (N). Such F$|$N bilayers have become
basic building blocks in a wide variety of spin based devices. We evaluate the
shot noise of the spin current traversing the F$|$N interface when F is
subjected to a coherent microwave drive. We find that the noise spectrum is
frequency independent up to the drive frequency, and increases linearly with
frequency thereafter. The low frequency noise indicates super-Poissonian spin
transfer, which results from quasi-particles with effective spin $\hbar^* =
\hbar (1 + \delta)$. For typical ferromagnetic thin films, $\delta \sim 1$ is
related to the dipolar interaction-mediated squeezing of F eigenmodes.
