I had an AMEX Blue Business card with an RF chip in it, transaction receipts had a completely different last 4 digits using RF vs magnetic. I called to see if I could get a chip+pin and they said yes except it's chip+signature. So at least U.S. AMEX is chip+signature. However, the card's chip "pin out" area is shaped smaller and differently arranged than the one on my bank issued card. So we apparently have two different "chip" standards and I don't know which one is actually going to get used.

Most US banks are going for chip and signature.

I've received two new cards in the last month with a chip in them - both were chip and signature.

When I enquired my bank about my EMV card, they informed it that it preferred Chip+Signature, but that it also supported online (aka "realtime") Chip+Pin authorization. It is not configured to support offline Chip+Pin like many european cards.