Yoni Heisler wrote a nice overview on TUAW about the Apple Pay's secure payment system.
Apple Pay is an exceedingly secure mobile payment platform. In fact, it may very well be the safest way to make any type of credit card payment.
What I find even more impressive, however, is that Apple has been able to put together a system that increases security while also improving the user experience - and, by the way, bringing value to the other stakeholders involved. There's also the issue of Apple getting the timing right.
In contrast, as Charles Arthur at The Guardian points out, Google Wallet misses many pieces of the puzzle. It doesn't use bank-issued tokens. It's difficult to use. It's 2011 launch was too early, as few retailers had plans to become NFC-equipped. And it gets worse - the article is definitely worth reading.
So like the iPod and so many of its other moves, Apple has again focused on getting it right over getting in first.