To start off, for all those who say Naruto's high speed movement in this chapter was the Flying Thunder God technique, you're wrong, for more reasons than one.
First of all, the Flying Thunder God technique is much like the Summoning Technique; in essence, it revolves around manipulation of space and time, something that Naruto clearly did not do. Next, to activate the Flying Thunder God technique, a person needs a special seal or "technique formula" to mark the destination the user intends to go to. Naruto did not do this either; he placed no seals, and did not have any seals ready on any weapons (such as kunai or shuriken); rather, he attacked Kisame simply with his incredible speed.
Although Minato used kunai to prepare the seals for the Flying Thunder God technique beforehand, anything can be used, so long as the proper seal is there. Immediately after Kisame opened the door to the training area where Naruto gained control of the Nine-Tails' chakra, Naruto charged at him without hesitation. Did he have any seals applied on Kisame, or anywhere else for that matter? How would he be able to do so considering Kisame was hiding in Samehada, and Naruto only sensed his presence when using the Nine-Tailed Fox's chakra, which gives him the ability to sense hatred and other emotions?
Now, everyone thinks that it was the Flying Thunder God technique simply since Yamato mentioned "the Fourth;" however, he could be referring to the Fourth Raikage, or the Fourth Hokage. Both have extraordinary speed, and when using Lightning Release Armor, A's speed and reflexes become comparable to that of Minato's. If Yamato was indeed talking about the Fourth Raikage, then some ask, how would he know about his abilities? It's quite simple. Yamato is a fairly experienced ninja who has witnessed many things during his life; just like the Five Kages know about other countries' leaders and heroes, so too would Yamato know about Kumogakure's current leader, A. For example, the Raikage knows about Kakashi - does he know him personally? No. Yamato probably heard about him as the years passed, and that's how he knows about him. After all, do Konoha ninja, or any other, for that matter, only know about their own country and their own people? They are familiar with places and people outside their homeland.
About the Fourth's speed, it seems that Naruto has not developed his father's agility yet. Yamato means to say that Naruto used too much force moving too quickly, and this caused his leg to get caught in the wall. But nowhere does Yamato hint that this is the Flying Thunder God technique; Minato had his own speed apart from his technique, as seen when he resuced Naruto just before he was about to be impaled by Madara. It was the same in this chapter when Naruto attacked Kisame. It was not the Flying Thunder God technique, but it definitely was high speed movement (perhaps the Body Flicker technique?). We will need more information as to exactly how Naruto gained this ability and what it exactly is.
