Some people have alluded to it before, but it seems quite clear that Kabuto is playing both sides on purpose. Both Madara and the Leaf Village are his enemies so eventually he is going to go after both. For now he is using Madara to get closer to Sasuke. Madara thinks he is keeping Kabuto on a short leash and has nothing to worry about. Clearly, Kabuto will eventually try to eliminate Madara completely. Just as obvious, it seems Madara is well aware of Kabuto's future betrayal but has enough confidence in his own abilities to let Kabuto do his bidding for now.amazing chapter i must say but here's a couple notes to point out.
1) a couple weeks ago we saw madara take on a new form, new look, new set of unknown justsu, and the same for naruto. now it is no surprise we will see naruto's new depth of skill ( maybe in sage mood.. one could wish ) but all the same it is soon to come. now madara has avoided having to show his enemy his skills till now. will madara continue to hide his skills or continue to gather abilities before revealing his massive power.
2)now this point of business comes more from a place of thinking about what the author is writing that being said... kabuto can not die in this up coming fight. no matter what happens to the other side he will live. justification?? kabuto is sitting on the last big mystery of madara's. now some have considered this to be the true madara proving tobi to be a fake. or maybe madara will be who he says he is and rather its a beloved character proving madara has has a fake shinobi posing as a hidden leaf ninja or something. but no matter how you slice it kabuto can't spill the beans yet, and has to stay around to rat out madara? thought????
3)final thought of the day. kabuto having tracked madara down left a trail of bodies which were sloppy and looking to be on purpose for that matter. we can assume by the path of dead ninja leading their way kabuto isn't looking to team up with the leaf village,but leading them to madara also shows an intent to stop madara as well. which prompts my last question. if kabuto does win the fight and takes bee or naruto (and even if he doesn't would or) will kabuto help madara or continue to get in his way??
It seems we won't see a clash between the two until the last coffin is revealed. Once that is out of the way and Kabuto no longer has leverage over Madara, we will see them fight it out. As many have implied thus far, most think that Kabuto will defeat Madara and become the final villain.
With respect to the bodies he left for the leaf, he is clearly trying to help the alliance as much as he can to put Madara at a disadvantage, which connects back to him playing both sides.