If he really wanted to give development for her he should start showing her having concern about her clan and showing some leadership skills since she's the heir of her clan but no let's just give a moment were she can do something for Naruto this is not a development.
she basically did the same thing on the Pain's arc.
Naruto is in danger wait i'll just go OOC.
Hinata wasn't out of character I believe. Its actually nice that she can be confident when she needs to be, and not a stuttering mess. And I have to say that it *is* development, mostly for her personality. Before she could not speak with Naruto properly and was hesitant, wouldn't look him in the face, etc. In 615 there's no stuttering, she isn't blushing up a storm, she's sure of her words, and looks Naruto in the eye the entire time (added that she has the balls to do all that while holding his face) Its even more than her confession, where she spoke eloquently yet had her back turned.
It isn't "going OOC" but really having an inner strength that comes out in serious situations. I have to give it to Kishi that he did succeed in transforming her nicely outside of what was typical for her shrinking violet character type.
But yeah I'm sure most of Hinata's development will continue to deal with Naruto-- it always has, and that's what I do dislike about it. She's a strong character, but a satellite nevertheless.