What part of this is on the bank? If you have a credit card, does that company have to participate? Or a debit card, does your bank have to participate? Seems like I saw more things saying this or that bank is participating than retailers.
Also, the way Apple works(not complaining) you'd think some of these big places that are saying there not going to accept Apple Pay(Walmart, Best Buy) would get pressured into by Apple. They could easy hold back product or something to get a place to accept I would think.
The bank has to agree to Apple Pay, this is required for them to authenticate the card you add. This could be the biggest hurdle in the long run.
Merchants just need to have the NFC readers, and turn that on in their merchant agreements. It won't magically make your Amex work somewhere that doesn't take it with a card.
But everyone hoping to use it needs to be more concerned about the bank end if you aren't with one of the major ones listed.
In my opinion, NFC will become more common, but you might have a hard time convincing "small town bank" to sign on.