On a more personal note, I will remember him best for his bold prediction in an article published in 1996 in the National Interest that China would become democratic by about 2015--a piece I still remember reading in my Chinese politics class as a college sophomore. He remained optimistic about China's political trajectory through the end of his career.
A fuller exposition on his long and storied career in government and as the president of the RAND corporation is here in the New York Times.