I think we're post-killer feature now... It's all about refinement. The camera will most likely be better, but only by a marginal amount of course... it'll be faster, be a little bit more power efficient, etc... I am not so sure we're due for any major design overhaul like we saw between the S5/S6 generations, so I'm fully expecting another iteration of what we saw in the S7 and Note 7.
Beware the crazy rumors.. 4500mah batteries, 10G RAM and 8K displays...