The summon's upgrade was probably from Sasuke nearing death, a common idea in anime. Personally, I think Itachi's was still better. Ooh, look at Sasuke's summon, it's got a crossbow, ooh, how kick-ass. Not.
Anyways, I'm seriously tiring of all these Sharingan techniques. Bad enough that there's the Eternal Mnagekyou, now Kishimoto goes and reveals another Sharingan technique?! I doubt it's a Mangekyou move, it's probably just a regular Orochimaru-style Kinjutsu. And speaking of Orochimaru, I ownder if he was responsible for all those eyes? The Senju thing is confirmed, which is just crap, man. Why can't Kishimoto keep the good guys unique anymore? First we get people ripping off the Kakashi implant idea, now a Wood rip-off! Come on! Poor Yamato, he's reputation is failing.
As I said before, I don't give two sh*ts as to who wins this fight, they can both die for all i care, but can't Kishimoto hurry this up? I'm itching to know what happens after this damn fight.