"Users can, with the aid of a GUI-based management system, force particular files and folders to be fixed ("pinned") in either flash or on disk."
I would buy one of the devices using this for this feature alone. No matter how good your detection algorithms are, it is nothing like the intimate knowledge the ACTUAL USER has on how they use their data. Pass the power to them and let them reap the benefits (or dig their grave) as they see fit.
Read my past comments. I called for this feature some 6 months or more ago.