While the attention and awareness brought to the G-spot is has increased over the last 50 years the spot it's self is not new and has been around as long as women have been and as been known of by the Ancient Taoist and Tantric Sex practitioners as evidenced in their writings where they make references to both the spot and female ejaculation.
This simple acknowledgment - that physical pleasure is a form of nourishment - is, I believe, one of the reasons why the Kama Sutra remains relevant today