NFC, iPhone, Apple Watch (iWatch or whatever it will be called)

Daring Fireball, as always, had a very thoughtful post (couched as a joke) on how NFC could be incorporated and be made more useful on a phone than it has been to date.

I don't know really know a ton about NFC but believe that the paypass, expresspay, etc. systems all use an NFC chip on the payment tag, card, etc.

John Gruber suggests that both the phone and wearable could have an NFC chip to allow this.  I would not mind a contactless payment device that was already on my wrist instead of in my pocket.

My question: is it possible to create a configurable NFC chip that allows it to take on the identity of an NFC chip that works with paypass or expresspay?  So I'm thinking that an american express customer confirms some credentials that allow the phone's chip to work with the relevant system.  As an alternative to configurable, I guess the chip could be static and the payment network is instructed to respect the chip and associate it with an account.  I think this is how google wallet works.

My issues:
- would one be able to link more than one account?  If so, how would one easily select which account to use?  Right now, selection is inherent in the tap as I choose which card or dongle to tap to the machine.  If a phone has credentials for more than one network, it seems that the ease of tap gets offset with the burden of selection.  What I want is what I have now: I have a paypass chip GLUED to my phone so I tap my phone to the reader with no need to enter anything on my phone (no app, no interaction, etc.).  This is WAY better than having to enter anything.  I might tolerate a fingerprint confirm.
- do the systems want to encourage or discourage others to create chips?  I can't decide.  On the side of encourage, it would increase use of the systems, make merchants more likely to use them, etc. (typical network effects).  On the side of discourage, it lowers barriers to entry (if it can be done on an iPhone, over time it can be done on ANY phone, or watch or whatever) and creates security risks (there is some authentication process where a phone is authorized to the system rather than receiving a card that is pre-authorized).

Amazon's expanding B2B efforts

The recent news regarding Local Register, Amazon's new mobile payments system, may be the next step in my pet theory that Amazon was designed NOT to be a retailer but rather to be the backbone for retail and take a margin on retail generally.  However, to create the scale and credibility needed to move into these businesses, Amazon first needed to create a massive retailer.  But making money from retail itself is perhaps not the true goal.

For example:
1) Warehousing and third party sales.  Amazon has expanded greatly into storing goods for third parties.
2) Fulfillment and Delivery.  Amazon acts as storefront and handles logistics interfaces for third parties.
3) Finance.  Amazon provides small business lending.
4) Cloud.  This is very well known.
5) Payments.  Now Amazon handles payments for goods that have no other connection to Amazon.
6) Devices.  Although superficially supportive of Amazon's retail business, these are equally supportive of Amazon's third party retail businesses.

What's next?  What does Amazon do that is easily portable and deliverable for third parties?