I know this is probably outside the scope of the product; however, the first thing I thought of was the need for comments to be attached/associated with a file transmitted back and forth.
As I already mentioned to a few of your teammates here in the States, I like the concept of the private cloud solution; but in a smaller scale as the IBM i disk is relatively expensive. It is also nice that this could be used instead of a DropBox, iCloud or any number of current competitors - the possibilities with internal security on IBM i with the documents and folders on the IFS are great. I see how this could be implemented as part of a light workflow solution and it seems like this could be part of a Composer processing sequence as well - for those who have already invested in that product.
I see comments on files to have some additive value. Not to make it a full-blown collaboration system (there are so many others out there); but I think there is goodness in something beyond just a file and folder's name (especially with the geo-location creation feature [which is way cool!]).
I expect this feature would escalate the complexity of the solution; but I think there are a number of use cases where it could be very useful.
HTH, *bg