Mobile payments using contactless technologies such as NFC goes beyond the transaction at the Point-Of-Sale, in terms of providing a context to my payment. Even though it maybe that it would be easier to take your credit card and swipe faster than taking out your phone, launching the app and then initiating a mobile payment, the advantages are as follows: - The app can tell me if for a particular retail category, I h…
The big players are never going to open up their NFC tag format so 1) the only app that will let you use your phone to act as your bank or credit account will be their official, locked down app and 2) the only app that will verify that the tag read constitutes a valid credit card is the official app (sorry, Square - unless they manage to partner with the big banks).
I do not think there will be open standards for letting indie developers into the purchase chain for NFC.