Right now, I dpn't really see anyone dying anytime soon, they killed a whole lot of nameless Konoha ninjas in Sand's attack, so killing anymore off would just make Orochimaru destroy Konoha with a thought.

Sakura won't die, and unfortunately neither will Sasuke because they, along with Naruto parallel the sannin (despite how weak Sakura is compared to Tsunade). Since all three of them are around, those two won't die either.

Hinata doesn't need to be killed off, her storyline is done and I actually doubt we'll see her again anyway. The same goes for about all of the female ninjas.

I could see Iruka dying, but it wouldn't provoke Naruto to kill, that's not what the whole show is about, this is not DBZ (though its starting to get close). Naruto would just kick the living shit and paralyze whoever killed Iruka.

How can we tell when someone is about to be killed? When they've had a fair amount of character development (like Chouji and Neji) and any questions we had about their past have been answered.