Until this thing available worldwide as soon as possible, it would be vaporware..
Contactless payment terminals are already widespread in Europe. From the video it looks like ApplePay uses the same terminals, there's nothing proprietary at the retailer's end.
Have to say, using a contactless NFC credit card at the moment is already very quick and easy. Not sure on the idea of pulling out my phone, opening up the Passbook app, selecting a credit card, and then operating TouchID while over the terminal sensor.
At the moment I can just wave my card (or my phone with a paytag stuck on to it) over the terminal and I'm done:
http://youtu.be/uElc6VKr3Lc?t=8s