Sorry I've been out of the Facebook app game for a while, but isn't there a Facebook API for photos? Couldn't anyone do what Facebook is doing here, leveraging the Facebook userbase and their unrivalled quantities of photos? Of course users would still have to discover the app as opposed to it being part of the stock FB experience, but this doesn't necessarily sound like the death knell for every startup who wants to build a social/collaborative photo album service.
