Next episode is filler and I also think 320 is also filler.
The reason that we have fillers is apparently Studio Perriot has their best animation team (the one which does the movies) animating the Madara scenes.
Given that they are taking this long, I hope it really is good quality when we get the canon episodes.
The rest of June has all fillers. I recommend re reading the manga so the filler become something extra. From that perspective you can look at them from just a creatvity standpoint. At least thats wat I do
This answer is most likely correct, Naruto helped Shino with Torune. Then the show went to Bee to see whats going on. The Bee situation is over, and Naruto is going to see Kiba, Hnata, and Neji. If you haven't seen it in te magna I wont spoil it for you.