Personally. The 4.7 is plenty to behold for me.
Oh I have no doubt that the 4.7 is great for many people. My point is that now Apple has satiated a certain market's desires and it would be pretty damn hard to go back on that (especially considering the success of the plus).
i honestly don't think phones are gonna get much bigger because then it just starts to become a tablet.
4.7" / 5.5" are the right sizes. also we don't need higher resolutions for a good while yet. 1080p is just fine.
i think the focus should now shift to the internals. bigger batteries, faster and more powerful cpu/gpu/ram etc. better cameras.