Too bad screens are using a good chunk of your device's battery. Reducing the radio and computation to close to zero may reduce consumption to 30-50% but it's not an order of magnitude. The batteries are here to stay I'm afraid - until we get some radically different display technology, along the lines of a color, 30 hertz e-ink.
This was more about having wireless power too (part of the parent comment). You don't need a 10 hour battery on something if you can power it wirelessly.
