This was an interesting chapter. I'm assuming kakashi hurt his hand trying to see what would happen if the new rasengan would clash with the chidori. I dont feel that this new rasengan will just flat out destroy the difference in power between sasuke and naruto though. In the kakashi gaiden they already said the chidori was an incomplete justsu because you could tell what the enemy was going to do if you were at high speeds. What if sasuke make the chidori a tracking jutsu which targets chakra. This way he wont have to use the sharingan. Even though he has never missed before, a new way to use the chidori with out needing the sharingan would conserve a lot of chakra.
Also, it funny watching everyone assume whats going to happen in this anime. If you watch a lot of anime the storyline will most likely seem static. They all pretty much have the same format. How many animes have you seen where the "power of friendship" is way more powerful than logic. Some times I wonder if these anime writers have friends the way they glorify friendship.
rant over...