How many Slams will Nadal end up with?

So he already has 4 titles at the French, 1 at Wimbledon and 1 at Australia. He is 22 years old. I think he easily breaks Pete's record if he doesn't hurt himself (which is a good possibility because he plays so physical). These are the totals I think he will end with at the least:

Australian Open - 4
French Open - 8
Wimbledon - 3
US Open - 3

It is my true belief that Rafa will end up as the best player ever when he retires. He is untouchable on clay, and his game on hard courts and grass has improved tenfold. He plays every point like he is match point down, and he just imposes his will on his opponents. In the long term, the only guys I see competing with him are Murray, Djokovic, Monfils (if he ever fully develops his game) and Tsonga (if he stays healthy). Your thoughts?