<my 1.5 cents>
I heard a story on my (excruciatingly long, holiday-traffic, maniacal-driver-ridden) drive home yesterday, on NPR somewhat related to this.
It was more focused on the medical benefits of such a chip, although the interviewed did express his feeling that eventual requiring of an implanted chip for day-to-day life was inevitable.
You can listen to it here.(Scroll down to 'Human Medical ID Chips')