Questions for Rob

Two questions in response to Rob's post, "Friends with Benefits." 

First, philosphically (setting aside the practical problems and costs for the moment), what would be wrong with the state adopting an "Intimate Associations Act."  These associations would be situated on a continuum between business associations and marriage (privileged domestic associations).  This form of partnership could be used by any two or more persons who decided to form intimate friendship (with unspecified rights and duties) whether sexual or not.  It could be used by two single brothers who want to share their lives in common.  It could be used by two sisters raising their dead brother's child.  It could be used by two or three friends who want to share life together.  And, it could be used by homosexual partners who don't have the benefit of marriage.  It would be irrelvant to the state as to why someone would want to form such an association and whether or not sex is involved (at least between consenting adults).

Second, you say "It is difficult to imagine marriage maintaining its privileged status (as I believe it should) twenty years from now if a significant portion of the population is ineligible."  Why?