In the latest software update pushed to Shield users worldwide, NVIDIA is allowing users to actually stream games remotely from their PC. Up until this update, the Shield was capable of playing graphically intensive games that were processed by and streamed out of your home PC, however you needed to reside on the same network.
With a fast enough internet connection, the updated GameStream service will allow you to have the same functionality as before, except that you can be out and about as well. NVIDIA are also enabling GameStream for laptops. The functionality is still in beta but it’s a great indication of things to come.
(Source: The Verge)