Just got back from a Meetup on experimenting with iBeacon and more importantly, developing BLE aware applications. Quite insightful.
Ironically, BLE (Bluetooth Low Energy), a marketing term coined by the folks at Nokia, is now supported by most of Apple's product lines, and some of the Android devices (though Android itself has limited supported APIs).
Apple's approach to iBeacons is quite interesting and provides a foundation for interesting development of applications (locale driven context) as well as integration with future devices (ala Samsung Galaxy Gear Smartwatch).
In the next 6 - 8 months, one can expect to see retailers starting to adopt this - thinking of some of the more digitally savvy ones like Burberry - where their iOS application transmits your size information while providing information on new items / trends / backgrounds as one moves around the store.
Interesting times, indeed.