Solar-powered robotic weeder

This is simply too much, a solar-powered robotic weeder, a Roomba for your garden?  Now the solar part is easy enough, although our gardens are pretty shady.  But how the heck does this thing decide if a plant is a weed or not.  And it's cute enough in a green Roomba sort of way, but this thing is tough enough to get grab grass or a dandelion, not to mention a red bud seedling.  Do any of gardeners out there buy this idea?  They show it sitting on mulch, can it perceive weeds or does it just stir things up? It can't possibly have enough AI to be selective, but having tried to train a few student gardeners, maybe it's possible.