The only problem is they are not fueled by cold fusion. http://www.theregister.co.uk/2009/07/09/eatr_beta/
"Robot land-steamers to consume all life on Earth as fuel Autonom-nom-nom-nomous technology By Lewis Page Posted in Science, 9th July 2009 12:06 GMT News has emerged of a milestone reached on the road towards a potentially world-changing piece of technology. We speak, of course, of US military plans to introduce roving steam-powered robots which would fuel themselves by harvesting everything alive and cramming it into their insatiable blazing furnaces." <more>
