In addition to this, the update also brings cloud sync. What this means is that your card information will be saved to your account (as it should already be anyways), and when you sign back into your Samsung account – perhaps after a factory reset of exchanging devices – your credit cards, debit cards, membership cards and gift cards will all be there and available for you to use for your purchase.
In the "What's New" page within the Samsung Pay app, the company lists that you can now add even more gift cards and membership cards to your account. This isn't part of the update (meaning those not on version 2.3 can still add in the new gift cards and such). It's actually part of a server-side update. But it's a good idea that Samsung added this to the changelog, so that everyone knows that this is possible.
Samsung Pay has been pretty popular among consumers and this is likely due to the MST technology that is used in their smartphones. This means that users are able to just tap their phone on the payment terminal and make a payment. This works even on older terminals that don't feature NFC connectivity. Meaning that Samsung Pay is accepted virtually everywhere that takes credit and/or debit cards.