The Iray plug-in for Rhino is in development now. NVIDIA announced that their beta program is open and they are looking for more registrations.
NVIDIA Iray for Rhino is a rendering plug-in for designers who want to quickly produce physically based, photorealistic visualizations.
Iray is integrated into Rhino, rendering directly within its viewports. It gives continual, realistic feedback as you craft your model’s form, materials, and lighting. Iray’s physically based capability predicts the behavior of real-world materials and lights. Accurate visualizations only need a minimum setup and specialized knowledge.
NVIDIA for Rhino supports the NVIDIA vMaterials library.