We'll see how it plays out, but I imagine the notion of a file will continue to decline, and end up replaced by APIs.
APIs continue to provide interoperability, but instead of having the user select a file to upload, they select an image through the Facebook API. This should ultimately improve the user's experience, but there are some downsides during this transition period (IE: photoshop touch lack of sharing features).
While you could argue FilePicker brings back the file, you could also hedge your bets the other way, and work as much as possible to abstract away the file. Instead of grabbing Facebook photos as a set of files, what if I could easily grab the set of photos than contain me and a friend?
This way if you start a new social network, in addition to network effect it would have that huge disadvantage to Facebook that no programs are willing to interoperate with is because they only know that proprietary Facebook API.
The problem is that it requires each application to have to wrap each API. You end up with a huge amount of redundant work, and in general a dearth of integrations as developers are lazy/reprioritize. For example, there are apps that support integration with Dropbox, but don't support Google Drive, Box, SugarSync, etc.
APIs continue to provide interoperability, but instead of having the user select a file to upload, they select an image through the Facebook API. This should ultimately improve the user's experience, but there are some downsides during this transition period (IE: photoshop touch lack of sharing features).
While you could argue FilePicker brings back the file, you could also hedge your bets the other way, and work as much as possible to abstract away the file. Instead of grabbing Facebook photos as a set of files, what if I could easily grab the set of photos than contain me and a friend?