An interesting article in Psychology Today talks about why more adult children are moving home, and some of the reasons why this is no longer a temporary phenomenon, but part of a larger cultural shift. Neither parents nor adult children feel embarrassment or a sense of failure when the adult children remain financially dependent well into their twenties or even thirties, as would have been the case a generation ( or even half a generation) ago.
You can read this interesting take on the not-so-empty nests of the Boomer Generation here.