Pascal is expected to be introduced in the first half of 2016 and this leaked driver mentions three specific GPUs with new compute capabilities, as well as the future Volta branch:
Now the surprising thing about the new GeForce 358.66 driver is that while checking through OpenCL runtime, the driver exposes two brand new compute capabilities on a few new CUDA architecture enabled GPUs. There are two unique ids, “-D__CUDA_ARCH__=600” for Pascal GPUs and “-D__CUDA_ARCH__=700” for Volta GPUs. Previously, NVIDIA has used the “-D__CUDA_ARCH__=500” for their Maxwell GPUs, “D__CUDA_ARCH__=300” for Kepler, “-D__CUDA_ARCH__=210” for Fermi and “-D__CUDA_ARCH__=200/100” for their first generation Tesla GPUs.On top of this, the driver package also contains references which indicate it features preliminary support for the Vulkan API.
-D__CUDA_ARCH__=600 -D__CUDA_ARCH__=610 -D__CUDA_ARCH__=620