Creating snow in After Effects has been updated on PVC.
You can use dedicated snow filters or particle systems to create snow that can be either stylized or realistic. There's filters built into After Effects like CC Snow, CC Particle World, and Particle Playground -- or you can use 3rd-party filters like Trapcode Particular (which is AE 3D camera-aware), Boris FX Snow, Cycore FX HD Snowfall, DigiEffects Delirium Snow, and GenArts Monsters GT.
Read the rest on PVC...
Also posted recently at PVC was the mini-roundup Animate a Photo Mosaic in After Effects.