Just what society needed: the love child of a grocery buggy and R2D2.
My first thought was "You can't even put consistently reliable wheel bearings on the things, yet you think it would be awesome to give them more computing power than it took to get Alan Shepard to his tee time?"
My second thought was "Have these eggheads ever seen the damage a tantrum-throwing toddler can inflict on a shopping cart that doesn't have a touch screen?" Which, of course, led to the vision of a future mom putting her kid in the WALL-E grocery buggy which follows her into the produce section before being hijacked by kidnappers running the HACK-A-KART app on their Androids and carting off her precious bundle while she's absorbed in selecting tonight's arugula.
I'd further note that, in an economy where even plain old dumb shopping carts are increasingly tagged like migrating harp seals and fitted with The Club to keep them from being stolen by winos or sold as scrap, how about you just let me push the cart the old-fashioned way and read my own handwritten grocery list, and y'all can then use the savings to knock ten bucks off my grocery bill. How's that sound?