Earlier quoted context omitted.
It would give a sense of how far they still have to go.
There is nowhere to go, not with the available physical space. I expect noise to get lower and lower and low light performance to increase, leading to sharper (due to less noise reduction) and less noisier images in the coming years, though, due to the small available physical space and small sensor probably always a step behind larger sensors (like the ones one would find in larger cameras). Maybe it will be possibl…
http://appleinsider.com/articles/14/01/28/apple-granted-two-...
And then there's the option of having multiple cameras taking the same shot, with different focal lengths (whether fixed or zoom) on each. You're still limited in dynamic range by the photosite size, but as we're seeing now, that's often not so huge a problem in many scenarios. One startup working on such a principle is Light:
http://www.imaging-resource.com/news/2015/04/18/photo-startu...