I'm 34 and I've never had photos developed. When I was old enough (14-15?) to care about taking pictures of things I had one of those Sony Mavica floppy disk cameras that could hold something like, I dunno, 30-50 pictures.
But, on the flip side, every time I goto Walgreens there's people getting photos developed.
(I'd be curious to run a straw-poll to find out how many Hackernews ever actually got "photographs developed"...)