Digital photo lenses that distort
I like fine camera lenses, but the best quality are very expensive. There are many things that are hard to do in a good lens -- you want a sharp image, of course, over the full flat plane. Over the whole image plane you want low flare, high contrast and low chromatic abberation (ie. red and blue focus in the same spot.) And you want low distortions.
Most camera lenses try to be "rectilinear." That means they try to make a straight line straight in the image. This isn't actually natural, due to perspective straight lines are not straight.
So I wonder if we might soon see a new lens where no effort is made to fix distortions or make the image rectilinear, and all effort goes into the other factors. You are thus expected, with every image, to do digital post-processing to get a non-distorted rectilinear image. That will mean some small loss of image quality at the edges of the image, but probably a less distorted image than ordinary lens physics can deliver -- and a lot less cost -- in exchange.
Of course, this would primarily be for digital cameras, but a film user could also use the lens if they planned to scan their film for digital processing, as most do these days.
Down the road, each lens might contain within it the specifics of its own particular distortions, and the camera might be able to fetch this and either process directly or store it with the image for post-processing. Indeed, the lens might be a cheaply made lens with distortions due to the poor quality elements, or it might be a fine lens with deliberate distortions. (I have wondered if some P&S digicams might be doing this already.)
Certain types of chromatic abberation might also be treated this way, if they simply change where the light comes to focus, and don't blur it. The camera would know that the red light is one pixel to the left when it creates the image.