After seeing a public policy talk on RFIDs, I can't help but wonder if we're headed for a very difficult and muddled situation with respect to privacy.
One reason for this is that there is already a large base of RFIDs out there. Couple this with the expected wide deployment due to WalMart and the Department of Defense, the lack of any kind of meaningful control and feedback over disclosures, and the lack of coherent policy, and you've got a potentially bad situation coming in under the radar, despite the efforts of researchers, watch dog groups, and public policy makers to the contrary.
It seems that one fundamental problem here is that RFIDs can be used for so many different things. They can be used as keys (think cardkeys), financial payments (think FastTrak tolls or gas station key fobs), inventory trackers, as well as anti-theft devices. This one-size-fits-all approach makes it difficult to come up with meaningful solutions that maximize the real benefit while minimizing the foreseeable risks.