Recently The Chaos Group has released a service pack for V-Ray for 3ds MAX which includes support for MAX 2013 as well as significant improvements to V-Ray RT.
For a complete run-down of the features of V-ray sp3 for Max 2013, check the video below, or the page at ChaosGroup here.
The latest V-Ray update features an extensive list of new features and improvements including: support for 3ds Max 2013, support for motion blur (transformation and deformation) with V-Ray RT and V-Ray RT GPU, optimized interactive rendering using the NVIDIA CUDA™ architecture in addition to OpenCL, new “Matte for reflection/refraction” option to the VRayWrapperMtl material and the V-Ray object settings, and support for Ornatrix 2.0