In store illumination certainly does need to be much higher (Lumens/unit area) than does street lighting. Right now it is done with a lot more florescent or halide lighting. It will take a lot more high brightness LEDs also.

My bet is that the commercial economics considering the long life of the lighting and the reduced heating and air conditioning costs are good right now.

One lesson I learned when I owned a commercial building and changed the lighting from T12 to more efficient T8 florescents is that I saved money from reduced air conditioning in the summer and I saved money in the winter because heating with natural gas in my boiler was much cheaper than heating with waste heat from the lighting system. The savings with LEDs will be greater than with Florescents.