The competitive android market:
There is a stiff competition between OEMs in the android market these days and unlike 2011-2012, samsung is no more the only android OEM player. In korea the company has significant sales but Apple comes out as the favorite in japan and china now. People want the iPhone more than any android device and this suggests that samsung is not going to steer clear to the record breaking sales figures. Even in America and europe, the iPhone is likely to fare better in terms of sales volume.
If we talk about the competition within android then in south asia itself, cheap android manufacturers are doing exceptionally well. Brands such as xiomi, micromax etc. are not only creating high configuration cheap phones but paying close attention to the aesthetics as well. Making money from this segment is not easy. Talking about the relevant market of s5, competitors such as sony and HTC have already rolled out their flagship devices and have been able to get significant sales too. It cannot be a clean sweep for samsung.
For android app developers the fingerprint sensor is of some use. If samsung provides an API for the sensor , we can surely expect to see some app innovations based on the fingerprint sensor. This is somehow a little far fetched but there is not much exciting in the device this time as well.
It is certain that samsung will sell a significant number of S5s too but like the previous year there isn't anything much exciting.