Regarding Apple Pay, there's no need for Apple to partner with any retailers, unless they're adding the button to their apps, which is not interesting in any way.
The interesting and unique thing about Apple's implementation is the partnerships at the network and issuer level. This allows them to emulate contact less EMV for existing cards without having to man in the middle like Google Wallet.
That means all the rewards and benefits of existing cards stay the same, but all of a sudden everyone gets secure transactions.
It's a huge deal and will make retailers install PayWave/PayPass/ExpressPay capable terminals.
This gets way more interesting when the Apple Watch gets launched.