At least to 4% according to today’s BBC news at http://news.bbc.co.uk/2/hi/science/nature/8660940.stm
The researchers describe how they compared the genomes of modern people from around the globe. “The comparison of these two genetic sequences enables us to find out where our genome differs from that of our closest relative,” said Professor Paabo.
The results show that the genomes of non-Africans (from Europe, China and New Guinea) are closer to the Neanderthal sequence than are those from Africa and it has impact on our behavior and physics.
Have I nice day, I will!