By using a capacitive touchscreen and a stylus that works on pressure, battery life should be saved. A high detection rate led to some nice looking graphics including curved lines that looked great on the experimental 7 inch tablet used for the demonstration. For this to work you need to employ the NVIDIA Tegra 4 and NVIDIA's DirectTouch platform. There was no word on which slabs will be employing this technology in the near future.
NVIDIA's Huang demonstrates capacitive stylus