I can already buy something with one click on Amazon.com from my laptop and desktop. And have been able to for some time. Adding that feature to a mobile phone will help, certainly, but that alone would not make a better shopping experience in my mind. I would still have to have that company's app, or browse their site in my mobile browser, which will always be slower than using a full fledged laptop or desktop.

I agree that if someone could make purchasing simpler on a phone than on a laptop/desktop (possibly through NFC or something) then it could be a preferable approach. But just storing credit cards isn't going to cut it in my opinion.