Allow "archiving" fonts
Some people (designers :P) have large font libraries, but don't use the majority of these on a day to day basis. Some applications (e.g. Inkscape) don't work well if you have too many system fonts, so other font managers allow archiving/disabling fonts temporarily.
It's unclear how this could/should work technically (especially if we want to expose the files #10), but it would be nice to have.