Mobile computing technology has brought about a plethora of different staff assisted applications including those where store colleagues can assist customers with more information than they ever had access to before. This has also enabled colleagues to place orders and take payment on the shop floor.
A few playful retailers have experimented with robots in store but until Artificial Intelligence (AI) advances to a point where a customer can have a meaningful two-way conversation with a robot, we would not expect this technology to gain widespread adoption.