Its impressive, but what I find depressing is that for it to be portable they have to use internal combustion engines (that have the side effect of making it look sound like a mosquito).
Its sad because I guess that makes fossil fuels still the most energy dense and practical portable form of energy.
Its am amazing achievement on the robotics side though.
http://www.youtube.com/watch?v=VXJZVZFRFJc