In a deployment that straddles the line between (admittedly very simple) digital signage and a low-data M2M application, one Sainsbury store in the UK is attempting to replace the standard price channel markers that run along store shelves with small wireless tags featuring a remotely-updatable e-Ink display.
Over the past 10 or 15 years we've witnessed a number of different companies attempt to tackle the price channel problem. Current paper-label channels are prone to errors and take a lot of man-hours to update. In attempting to address these very real and expensive issues, we've seen supermarkets and big box retailers turn to LCD character displays, dot matrix screens and now e-Ink. And while the technology has certainly improved (for example, it's possible to power many of these tiny devices wirelessly by harnessing the extra radiation from the fluorescent lighting that most stores use), the tech is likely still far too expensive to see mass adoption. Case in point: a developer kit for a small e-Ink display still costs several hundred dollars, and that excludes fancy power and networking options that would allow each label to be completely wireless.
Of course, it's also possible that an upgrade to the price channel itself could feed network connectivity and low-voltage power directly down the aisle obviating the need for such tech, but that's another infrastructure cost that needs to be included when evaluating when and where the ROI is for this type of application.
There will definitely come a day when price labels, store signage and even product packaging will be electronic, animated and remotely controllable. But based on today's technical limitations and the cost of being an early adopter, I think it's still a few years away.