This is one of the most scary yet fascinating things I have seen in some time. Forget bipedal robots, this quadruped robot/pack animal - BigDog by Boston Dynamics* - is quite something to behold. The Tank and aircraft changed warfare, along with rapid reaction motorised units, and this is part of the new battlefield environment, I should not wonder. Pack animal? I suspect it will go hunting for people very soon. Put a big pair of mandibles on the front and you will scare the living bejeezus out of anyone who sees it scuttling down the street gnashing away.
Reminds me of a Bug from Starship Troopers.
* Cyberdine Systems?