I think it looks like a really interesting technology, but it's still in the realm of research and academia. They're correct in that it demonstrates device miniaturization and they look like they're pushing the boundaries of printed circuit board sizes. Also the point of these devices seems to be to demonstrate that it's possible to make electronics capable of unpowered flight. 

On the practical side, I'd say the devices are more of a proof of concept. The electronics in a system can usually be made very light, but all your weight and size will come in the batteries and then the enclosure.  You can achieve something very similar by using a technology called flex/rigid PCBs which are already commercially available and can be custom ordered online. These are commercially fabricated circuit boards, typically used in mobile phones, that have a rigid part where the ICs would be mounted and a flexible part for interconnect, wiring, or mounting discrete components like resistors and capacitors. You'd be able to make these very light since they use a very thin polyimide (high temperature plastic) substrate and you can fabricate in the same winged form factor as what the researchers used. It'd be interesting to see if they make the mechanical files available to others. 

Akiba