I'm going to have to disagree here. Like Hotsuma said, Naruto can still increase his strength without powering up. He can do it through training, experience, and learning new jutsus.Alright Hotsuma, here's my response to what you've been saying in both this and the raw thread. You say all this powering up and usage of alternate power sources is very dbz-like, and you don't like it. You also you say you'd rather see inventive and cleaver fighting as has been the staple of the series from the get go. Well, let me ask you this: how clever and inventive can you possibly get by staying at the same power level? Ingeniuty can only take you so far if you don't become stronger. Naruto would never have beaten gaara if it wasn't for the summoning technique he learned, regardless of his cleverness. Same thing if he's put up against someone like a jounin, ingeniuty won't be enough for Naruto to succeed at this level. So "powering up" is a necessity. The extra power when coupled with ingeniuty (how many times have I said this word already?) will make for far more interesting fights then we've gotten to see so far.
If you look at the really great shinobi in the series, the jounins, hokage, and sannin. They are all the most skilled and powerful ninja in the series, yet none of them require transformations or power ups to be great. They are all great because of their talent as ninja. Will we never see Jiraiya or Kakashi transforming to win a battle.
Don't get me wrong, it was cool to see Naruto go beserk against Haku and the first transformation agaisnt Sasuke. To me that was Kishimoto telling us Naruto is pissed as hell and ready to kick some ass. But this second transformation is overdoing it IMO.
Also, something that bothered me about this chapter. I loved seeing the sharingan in action and getting look at what user sees. But would the the fully developed sharingan really make Sasuke that much stronger? And by stronger, I mean physical strength, not powerful. I can understand that it allowed him to follow and predict Naruto's movements, but at best, it should have only allowed Sasuke to dodge Naruto's attacks. Having the 3rd doujutsu should not have allowed Sasuke to drop Naruto in only 2 hits. His attacks should not have done that much damage to Naruto if in 229, Naruto defelcted Sasuke's katon with just chakra.
I'm sorta rambling now, but you get the idea.