The NFC-enabled version of the LG Optimus Net is apparently on its way to the US, expected to land at both Sprint and Virgin Mobile quite soon. It will be sold at those two carriers as the LG Optimus Elite. That name is a bit funny, since the phone is anything but high-end. Or elite.
The original Optimus Net was announced in July 2011, so it's not even a particularly new smartphone. Sometimes though, for unknown reasons, some handsets take many months to reach the US (case in point: Samsung Galaxy S II).
Unwired View, LG Optimus Net with NFC headed to Sprint and Virgin Mobile as the Optimus Elite