One of the major factors in dealing with the extensive amount of data is being able to find it when you want it.
To that end, I think that something like BeFS, or the always-upcoming WinFS needs to be the base for information management in the modern era.
Why would I want to look through a file system to find my data? The first thing that the iApps do is put a searchable index with metadata on top of the existing file system, and then do their best to hide the file system from the user. With BeFS, you had that built in to the file system itself -- usable, extensible file metadata and whiz-bang searching. A file system growing attributes of a database management system. So, your apps would get these data management features for free, and you could spend more time building functionality into the app itself. Or getting on with the rest of your life.