Well, some sensors could generate just a few bytes every second (heart beat measurements), while others could generate lots more (stress sensors on bridges). Video sources will be much larger sources of data. Crunching video may create significant savings, heart rated data not so much..
Okay, the concept looks like a "distributed" cloud computing to me...whether we call the local cloud, the RuBAN M2M system in this case as "fog computing" or something else. Btw, a thought that occurred to me...can this M2M system be used for car2car communication for self driven cars?