A nice advantage Apple has in this area is their retail stores. They can test (and already are testing) mobile payments in their own stores before rolling it ou

A nice advantage Apple has in this area is their retail stores. They can test (and already are testing) mobile payments in their own stores before rolling it out publicly. One problem they will face is that if it's tied to iPhone they are severely limiting the number of people who can use it and if merchants have to pay for any hardware for their stores they will go with the mobile payment provider with the largest market share.