While it would be very complex to save data for individual users, it would provide the ultimate experience for a person managing large portions of content within the text editor.  I've seen something similar at work using Gmail, where every few minutes your unsubmitted email will be saved automatically to your drafts folder.  I know that this would involve working with a core structure (such as DNN in my case) to create separate temporary user data.  I also believe that Cutesoft is leading the field in terms of text editing, and this feature would blow the competition away.