This registry setting simply toggles the "Hide protected operating system files" checkbox under Folder Options. If you wish to verify this, keep both regedit and Folder Options open at the same time, check or uncheck the box in Folder Options, then refresh the registry and you'll see ShowSuperHidden change back and forth from "0" off, to "1" on.
Case closed.
Superhidden files are simply files with the system attribute set.
A better question is "why" when system files and hidden files are being displayed, some desktop.ini files still do not show up in Windows Explorer. I'm researching this now.