Clever technology, but I can't help thinking there may be consequences to pumping out this much energy into the RF spectrum.

Our bodies are made up of vibrating molecules and there have been links between cancer and cellphones that are held close to the body for long periods of time.

There has even been studies showing that cellphones may be causing infertility in men: https://www.ncbi.nlm.nih.gov/pubmed/17655195

Cellphones only output around 500-600mW of power. The Energous/WattUp device transmits 15W @5.8gGHz for 5ft distance; Ossia Cota 8W @2.4GHz for 1 device; Wi-Charge 10Watts of Infrared using a Class 1 laser (which sounds the safest).

These devices do sound wonderfully convenient, but nobody knows what long-term effects they may have at power levels many times those of cellphones - which are having unintended effects on some people's bodies.

Sources...
Energous/WattUp:
http://www.tomshardware.com/news/energous-wattup-wireless-charging-haier,27944.html

Ossia Cota:
http://spectrum.ieee.org/energywise/consumer-electronics/gadgets/ossias-cota-wireless-power-tech-promises-to-enable-the-internet-of-everything

WiCharge:
http://spectrum.ieee.org/tech-talk/consumer-electronics/portable-devices/wicharge-promises-phone-charging-by-infrared-laser