Tegra is an Nvidia SoC for mobile devices. It integrated an ARM Cortex CPU and a GPU, and is used in robotics projects, for example: http://myzharbot.robot-home.it/blog/
ROS (Robotics OS, see http://www.ros.org/) is targeted at embedded systems. It uses message passing for inter-process communication and can coordinate a robot's software stack or even multiple networked robotic agents.
Just a project idea
The aim of this project could be to design a robotic system that combines the two.
Unfortunately, it won't be possible to try it out on real hardware, because we don't have a Tegra devkit.