I believe that this article by Amartya Sen published in the New Republic makes some tremendously important points about the future of human rights law:

The Universal Declaration of Human Rights made its contribution to practical reason and global politics in four distinct ways. First, the Declaration took the firm view that human rights do not depend on legislation for recognition. People have these rights simply by virtue of being human. The contention here was that the acknowledgment of a human right is best seen not as a putative legal instrument, but as an important ethical demand–a demand that everyone should have certain freedoms irrespective of citizenship, nationality, and location. Such a recognition would lead to fresh legislation rather than await it. The Declaration championed the priority of morality to law. It constituted an open invitation to all to re-organize the world in such a way that the basic freedoms recognized as rights would actually be realized.