To me this is like harmonizing mail and e-mail. It's not a one-to-one swap or replacement, although that is the overall intention. The technology will be phased in or out respectively based on advances in infrastructure. ie we will likely always require notaries to some degree so that we have witnesses to testify if documents are called into question in a court proceeding. This doesn't have anything to do with mail or our need for a mail system. So contrasting, the day we are past the tipping point on device-based payments, there will no longer be a need for payment cards.