Passbook can't read data from touching things. It could also never transmit a Geo intent to my car GPS using a cheap IC on both sides.
Payment and loyalty cards aren't the whole story, but Japan and others had no problem doing this ten years ago.
Passbook and NFC exist on different layers. The exciting prospect that Passbook holds is as a wrapper -- a mobile wallet -- that can ultimately include things that work via NFC, when at some point the API is extended to do so.