Filecoin would be an interesting solution, but is it the right one? I usually upload images (e.g. screengrabs) to embed them on discussion boards, and (semi-) permanency is important. However, uploading and storing on imgur is free of charge, so I don't see why people would switch to an IPFS solution, where they need to pay. So an in-app or in-browser solution might be preferable: the pubsub idea for the whole community would be nice, of course, but I can also think of a "pin-at-access" solution, i.e. if a user accesses the image (or rather: a webpage containing this image), his browser will auto-pin it to the local storage of his in-browser node, ergo it's being distributed only by those who accessed the file. Could cause problems, if the webpage isn't visited by many people, but that's an inherent problem in IPFS, it seems… distribution is great, permanency might be a problem.
Users would need some sort of "clear ipfs storage" functionality, though, or auto-clear after 1 year etc.
For photo collections, high-resolution stuff, etc. I can see a market for Filecoin-based solutions, but for a quick grab not so much.