This is putting the cart in front of the ox yet again. A few mails up
Aryeh and Gregory both come to the conclusion that automatic
flattening is useless.
Yet category flattening would be a prerequisite to intersections.
The only way to get proper intersection is manual flattening i.e.
atomic categorization. As long as nobody is pushing commons _hard_ to
change their categorization system _nothing_ will happen and we'll
meet on this list again in about one year repeating the same
discussion.