I don't know if anyone noticed this, but when Itachi and Kisame were talking about losing their lives in a "fight," it seemed like they were talking about Naruto.

Notice:



Then, a few moments after that quote, Kisame says this:



After looking at these two shots, it appears that they are talking about losing to Naruto. I mean, he does have the Nine-Tails in him, so maybe if Naruto was about to die, the fox would lend a huge amount of Chakra to him, allowing him to kick Itachi, Kisame, and whoever else's ass.