Its been a common practice for CGI rendering workloads (which are suited to distributed across GPU/CPU resources) for a few years now - you install client software on machines on your local network to use their CPUs and GPUs to do the job quicker.
For example, Keyshot is a real time ray-tracing program. Input a 3D model and assign materials and lighting, and the output is a photorealistic image:
KeyShot Network Rendering allows you to take advantage of your network’s computer resources for rendering images, animations, and KeyShotVR’s. After the simple installation process, any user with KeyShot can send a “job” to be rendered on the network. The jobs are organized into a queue that all users can view. Jobs can also be sent from the internal KeyShot queue to network rendering.
I didn't read the article as meaning that the the nVidia cloud will use *your* compute resources, a la Seti@home or Folding@home :)