Yay! I can now discuss how I’ve been creating some of my layered materials with iray! It’s a new layered material that has now been publicly released. It has a LOT of great features (SSS/Back scattering/Translucency, coatings, dispersion, etc.) all wrapped into one convenient source. You can download this new material from the nvidia ARC website HERE.
Update: If you’re unable to download the package from the nvidia ARC website I put a copy of the package on my server HERE. The PDF document included in the content said redistribution was alright as long as it was “done so in it’s entirety and without modifications”.
NOTE: And before someone asks, no it’s not compatible with mental ray at this time.