As I interpret the article, it's not about the offline payment market, it's about being able to buy -anything- as an "in app" purchase, e.g. in the Etsy app you'd be able to just buy stuff with no friction because it would use your iTunes account.
I think it's about both. For example, the article mentions Restaurant sales. This would have to take the form of an iOS app that somehow interfaces with the restaurant's POS operation.
There are many existing restaurant apps[1] that do this now (interface with POS, pay with CC), it isn't a big leap to think that it would be easier for me to order a burrito with my iPhone by clicking 'Pay with my Apple Account' versus having to enter a CC number.
