Of course it's not an easy feat, but he's got already 6 and that makes him one of the best players in history, a legend. I'm happy with that even if he doesn't win any more, though I'm sure he will win a lot more. Nowadays these guys make it look easy to win a slam because there are basically 4 contenders winning them all the time. But it's a freaking stat.
Yeah I think he will certainly win many more slams, although I'm not so convinced that he will catch up with Nadal is all. I think last year showed us how quickly things can change in tennis.