The "portable computer system" is described as a small computer that is about the size of a USB memory stick.
Nvidia's filing outlines the idea of packing a Tegra processor, Flash storage, RAM, at least one USB port, and other interface types such as a parallel port, a serial port, IEEE 1394 (Firewire), VGA, HDMI, S-Video, AV, DVI, LAN and WiFi into a package that is just 40-60 mm long, 10-20 mm wide and 5-10 mm thick. The feature set would be comparable to a entry-level computer system with limited storage and cloud connectivity.
Of course, it would not be a powerful local gaming rig, but most likely enough to bring along on a key chain. There is no display; the idea is to plug the device into an LCD or TV to be used as a display or into a regular computer to perform simple computing tasks much more efficiently as the device will consume just about 10 watts.
One could argue that much of the potential features are already covered by smartphones, but this Nvidia Tegra system could be substantially cheaper than a smartphone. In volume production, Nvidia could push the bill of materials well below $100, which could make it the most affordable new computer on sale.