As image processing becomes more and more powerful, it will be easier to fix and correct images. It will even become a simple task to take photos in places that it once would take a professional photographer, and a swath of lights to photograph.
As memory become cheaper, more compact, and cameras improve, we may very well move towards a future where every moment can be recorded on video, at resolutions so high, stills can be printed at current photographic resolutions.
Let's think about Google glass, not the version they are working on, but the concept and potential for 5, or 10 years down the road.
So, you're at your daughters ballet recital, and you a minute and a half through her routine that you forgot to start recording it. No bother, the camera on your head keeps a 10 minute buffer of video recorded, you flick your eyes to control the unit, and ta-dah, you've got the whole performance on video. Before she has even finished bowing, you can send the video to your friends, and her grandparents. Later you can watch it frame by frame, capture her at the height of her pirouette, remove all those other dancing kids, fix her eyes because she's blinking, and print the photo life size to be framed over her bed.
What possible purpose would still photography have in this sort of world? A world that could, and probably will exist.
Photography would be a relic of the past like the lemur; a reminder of where life used to be, stranded on an island isolated and removed from the evolutionary catalysts.
Oh dear. I feel like I've written myself into a corner. I don't know what use photography will have either.
Perhaps it is this.
For myself (I can't see inside anyone else's head) memory is broken up into images, iconic moments that define meaningful people, places, and events in my life. Perhaps this is why I love photography so much, it is a physical embodiment of memory. (Film can be held, and printed, while digital can still be manipulated through the computer as a medium)
Photography will always exist in the same space as painting, and drawing. It is a powerful and unrivaled representation of memory, and vision. No two people experience or see the world exactly the same, and I believe photography will find a niche and survive through the human need to express that vision.