Ok Color. How about solving the more basic (and important) problem with photos?
sethlevine.com
sethlevine.com
+100 for a spot on idea.
(and no it's not just dropbox for photos - it should find and deduplicate and centralise them. Plus it should be able to read the libraries of all of the major photo organisation apps - iphoto and all the others)
I've lost pictures in the past due to things that it's really hard to repeat with this version. The act of adding a photo from "share" into dropbox automatically makes the copy exist in dropbox's cloud (which is S3, I suppose) and my computers that sync with it. It's deleted from dropbox (but will stay for ~30 days) and placed into a work directory until I manually delete it by a process that places it in S3 first, then my local couchdb, then replicates that couchdb off site. If I'm home (or at least, my computer is), it also replicates to my laptop immediately, otherwise I'll eventually pick up the pics.
Hopefully I'll get bored with reliability and start making new features again. :) I'd be glad to help you out if you want to try what I've got, though.
Plain image files are fine on the way out of the camera (and maybe via a laptop), and on the way to the Internet (which will use low-res .jpgs with embedded metadata), but my central repository is currently Lightroom, which doesn't like opening up its database.
Lightroom can, however, talk to external photo services through a plugin system; its Flickr and Facebook exports work like this. So maybe your photo app is another of these services, as far as Lightroom is concerned.