>http://www.businessinsider.com/tom-tato-grows-potatoes-and-tomatoes-2013-9
>
>http://www.stuff.co.nz/nelson-mail/features/lifestyle/9218071/Potato-Tom-opens-fresh-doors

I read about this yesterday. Probably works because potato and tomato are closely related genetically (family Solanaceae).
But the process to create the plant is so expensive ($24 for an annual) that it will almost certainly remain just a gimmick for apartment dwellers.