The payment industry is evolving rapidly now. The credit card in your pocket that used to do just one thing will soon do many things, and be configurable. Its not clear yet how payment 'apps' will be spread but they are coming. Your card, linked to internet services, will do more and have more flexibility, both in when/what you can pay, but also with notifications for when something is wrong. It is possible someday that you can login to your bank's website and 'drag' new functions into your card. I believe though that most new functionality will reside in the cloud and not an actual snippet of code in your card. But you never know. Innovation is rapid now in this space.
Cloud-based payment solutions always have some risk of fraud and hackers, but your biggest risk was, and will remain in the future, at the point of sale. Every time you pay at a restaurant or any retailer and the card leaves your sight, there is the chance that someone is recording your information. A robust cloud-based service will have less risk than your local restaurant.