This would be similar to how eRoom maintains document edit history or how P4 does source control. 

This will allow a user to view doc history, diff, revert etc. 

For shared documents document history will also maintain history of which user made which change, who has viewed the document, edited the document, is yet to see (if the document is shared explicitly with a set of people).

This will set the stage, after more features are added, to provide an alternate to eRoom, Confluence etc.