The SAP Future Retail Center researches usage scenarios with RFID tags. I had the chance to visit it thanks to the Alumni Wirtschaftsinformatik of the University of Zurich.
The technology is already used in closed systems, e.g. during the supply chain on palettes. But there are still some technical issues that prevent RFID tags from being used on every product in retail stores:
A lot of the demonstrations did not work at all.
When scanning a shopping cart, the scanner only recognized 98% of all products.
RFID tags are still too expensive.
There are scanning-problems when the shopping cart contains certain materials. For example:
water (orange juice etc.)
metal (also Tetra Paks)
The market for RFID tags is still fragmented. Most vendors only sell scanners, or tags, but just a few vendors sell everything.
Having in mind that RFID retail stores are a hot topic for years, it was astonishing to see that the prototypes are more a proof-of-concept than really ready for the market.