They could add a "buy a good photo" button (like those guitars with built in radios?

)
They analyse your photo and sell you a similar but better one - or buy yours to sell to others.
Or possibly a "reap your soul" option for selfies. As some natives always suspected, take a picture, take the soul.
On a more serious note, add gyroscopes to the camera for better image stabilisation, especially when filming. Maybe even for motion capture. The hyperlapse app just proved it can work and that is a feature I would really love to have (besides better movie quality).
Edit: DOF app could be nice. Or adding it to live view, like thin lines at front and back of that live focus thingie.
Edit2: Achievements as in steam games to show off to your pals (like "Cliffhanger - I dropped my camera 50 times before it shattered"