Samsung Galaxy S5 also has fingerprint scanner. To enable functionality of fingerprint reading requires adding new hardware that leads to increase in cost of the device. So a fingerprint scanner will not be a part of all devices unless it becomes cheap enough. (E.g. previously only very expansive phones had camera but once cameras have become cost effective they are part of almost every device now)
Giving a functionality to scan fingerprint and use it as payment password can be achieved with a simple program in mobile and soon it might be a part of Samsung phones (or other brands) with fingerprint scanner.
