While at Macy's today I found some very pretty slips that in the past were not there. There are not enough of us buying them to cause Macy's to carry them so one must assume that more women are wearing them. Not because of the way slips feel, but as a way to complete their look.
I think that as the population grows older and clothing styles change we may see the return of slips and other foundations. As GG's become older they also become more modest and try to compensate for gravity. I don't know any (well only a couple) women at 60 who are still wearing the same fashions they did at 20.