1. Plastic-substrate screen
Having developed its plastic-substrate OLED technology, one would think that Samsung might want to use it in its next flagship phone. It's the same tech that allows Samsung to produce flexible/curved screens such as the one on the Galaxy Round, but we don't imagine the Galaxy S5 with a curved display. Rather, It might be beneficial for Samsung to use a plastic-substrate screen, as those are more difficult to break than glass-based ones, plus it'd allow the company to make the Galaxy S5 thinner, or fit a larger battery. Interestingly, recent leaks are suggesting we might get a 5"+ display with a breathtaking resolution of 1440 x 2560 pixels.
2. Fingerprint sensor
Sure, we still don't know if fingerprint sensors are really going to take off, but if there's even the slightest chance that they are, we're sure Samsung isn't going to miss this opportunity. Now, putting a useful fingerprint sensor on an Android phone would be a bit tricky, because you have to take Google into account, which is where many of the input passwords on an Android phone go. Most importantly, Google will have to integrate fingerprint authentication with the Play Store, in order to enable such functionality on the Galaxy S5, but hey, nothing is impossible. Sooner or later, Google should add such an option for handset manufacturers to take advantage of.
3. High-resolution camera with lossless zoom
We're seeing more and more of this feature lately, and we hope the trend will continue. With the advent of super high-resolution camera sensors, manufacturers are able to build 2x-3x lossless zoom capabilities into their phones. The Galaxy S4's 13MP resolution won't allow for such functionality, but if Samsung bumps the megapixels to something in the lines of 20MP in the Galaxy S5, it can easily add a taste of lossless zoom, and that would be lovely.
4. 1080p video recording at 60 fps and OIS
The GS5 will get a new, faster chipset, that's a given, and with it, we hope Samsung will also add 1080p video recording functionality at 60 fps. The LG G2 was among the first smartphones to show us the goodness of 60 fps video recording, and we have to say - once you start shooting your video in 60 fps, there's no going back - it's that much better. So, naturally, we'd expect Samsung to build this into the Galaxy S5. As far as optical image stabilization (OIS) goes, well, most of its competitors now have this useful feature, so we hope Samsung will adopt it as well!
5. Premium build quality
We understand this may be too much to ask from Samsung, but it'd really be wonderful if it can give the Galaxy S5 a bit of premium design. We've seen well-made products by Samsung before, so we can't see the reason why it insists on making its Galaxy phones so ordinary and uninspired, in terms of both looks and material quality. If not the whole body, then we hope that it can at least add a few classy elements to the device, like a frame from real metal, for example.
6. Always-on voice commands
There's no denying that Google Now is becoming an increasingly useful feature on Android phones, but right now, there's this inconvenience that requires you to first initiate Google Now and then say your command. Motorola has found a solution for this with its dedicated natural language processor in the X8 chipset, which enables always-on voice command capabilities. Hopefully, Samsung will go the extra mile and incorporate such a solution in the next-generation Galaxy flagship smartphone!
7. More accurate color reproduction
The AMOLED display of the Samsung Galaxy S4 is impressive at first, there's no doubt about that. However, it'll also appear as highly inaccurate to the trained eye. Should you happen to put the GS4 next to a phone with a quality LCD screen, you'll immediately notice that everything is somewhat greenish and bluish on the S4's display, be it saturated or not. We do enjoy the perfect black level and vivid visuals, but it'd be more than welcome if Samsung gives its best to tweak its AMOLED technology and make it appear truer to life. It seems the company has this in mind, seeing that it's created the special Professional Photo screen mode, which does bring the colors much closer to reality, but the overly intensive green color is still a problem.
8. Better outdoor visibility
Another weak area of the Galaxy S4's screen was its outdoor visibility. AMOLED displays typically have a lower brightness output compared to contemporary LCDs, which causes them to be harder to view under direct sunlight. Thankfully, we've seen a substantial improvement in this area with Samsung's Galaxy Note 3, which is much easier to view than the GS4. Having this in mind, it seems very likely to us that the Galaxy S5 will also benefit from this improvement, or why not take things even further!
9. 64- bit processor
Word is that Samsung is almost ready with its own 64-bit chipset. Does this seem like a likely addition to the upcoming Galaxy S5? Well, absolutely! Of course, we aren't so concerned with the type of architecture - we're much more interested in whether or not it's going to SCREAM, but we'll see...
10. Deeper, stereo speakers
Sadly, it's not as likely for this idea to materialize, since Samsung hasn't traditionally paid that much attention to the loudspeakers it puts on its phones. That doesn't mean they are necessarily bad - the speaker of the GS4 is actually pretty decent (for a smartphone speaker, that is), but won't complain at all if Samsung decides to step things up by adding an additional speaker for some stereo effect, and why not even make them sound a bit deeper, like the BoomSound speakers of the HTC One series? Samsung probably won't go for such a big effect, seeing that it'll likely want to retain the slimness and relatively small footprint of the Galaxy S, but still, we'd definitely appreciate it if it manages to put a better-sounding speaker (or speakers) in the Galaxy S5, and make it a bit more competitive with HTC's offerings in that respect.
11. Redesigned TouchWiz UI
The Galaxy S3 brought us the TouchWiz Nature UX, which was a substantial upgrade to Samsung's Android UI. Since then, the manufacturer has added slight improvements here and there, but most of the UI has remained largely the same. There aren't any indications about this yet, but we sure hope that with the Galaxy S5, Samsung will once again overhaul its user experience and make it a bit more modern, intuitive and uniform. Did we mention polished? Oh, yeah, that too, seeing that it's one of the weaker aspects of Samsung's software.