OnePlus is one of a company where they always try to match desktop grade performance for their smartphones particularly with the latest OnePlus 4, tagged as the 2017 iPhone killer.
This in the sense, the phone maker always tends to maintain the standards of implementing the latest and the highest end hardware. This makes it a challenging to task to speculate things.
The company has continuously managed to stand out in the market by offering insanely high-end and best hardware at mid-range pricing segments. This is widely true due to their tagline being "never settle."
Hence, it is staying true to their tagline. Even in spite of all these, probably OnePlus has surely got something to bring up the same level of excitement among their smartphone fans.
Considering the target audience for OnePlus 4 and the price target which is usually around $350-400, it's pretty safe to assume that even if there's a price increase for the following year by another 50-60$, users would pretty much see similar hardware that's implemented in most of the smartphone flagships of other brands.
Taking this into consideration, the market might see an improved processor possible at that time. The Snapdragon 830 perhaps? This is considering that OnePlus 3T is supposedly coming out with the 821 chip.
It's highly possible that the successors to the 820 and the 821 chipsets would likely be something like Snapdragon 825 and the 830. Maintaining their release schedule for all these years, it would likely see a mid-2017 release for the OnePlus 4 if not, early April like always. But for the moment, it's only all a rumour.
In terms of memory, there are phones already equipped with 8GB of memory. While it's clearly seen a jump ahead of that, 8GB of memory is what's ikely possible in OnePlus 4 as well. They're manufacturing a smartphone not a compact computer.
That would be really insane if there would be more memory added than what's required but since that's what has happened in the last two years, it's still possible that OnePlus will go crazy again.
Apart from these, a 2K display would be the ultimate dream to make sure OnePlus 4 as a daily driver smartphone. This would significantly improve the VR divison as well.
