Right now, in order to get the benefits of NVIDIA's CUDA, you require a GPU from NVIDIA capable of this - any new GPU off the shelf will do it, but up until now that has been a limitation.
NVIDIA revealed that it's going to start to support x8 processors as a target for CUDA applications - what this means is, any applications written to support NVIDIA's GPU's for CUDA for compute applications will now be able to run on standard x86 CPU's - without the need of a GPU.
It's strange of NVIDIA to do this - but it's also a good move. For CUDA applications - an NVIDIA GPU is absolutely amazing at smashing through the compute app, but allowing it to run on an x86 CPU is a good move. Solely because it'll show just how much an NVIDIA GPU helps.