It seems to me that Madara's visit is trying to keep Naruto away from Sasuke while he's setting up his Nefarious plan. Also doing some info gathering. He probably thinks that Naruto is the only one who could snap Sasuke out of his Murderous depression like he did with Pain.

I wonder when Kabuto is going to make an appearance again. I always liked his character, Evil, Intelligent and a little Crazy.