I highly doubt Sakura was planning in using Naruto as a tool to bring Sasuke if that's what you mean by saying" using his feelings" thats giving the idea for a very angsty fan fiction story. Sakura clearly told Naruto when he failed to bring back Sasuke that next time we'll do it together not I'm counting on you next time which is the opposite meaning that she's going to let him go after Sasuke while she stands on the side lines doing nothing (although that's what Kishi has done with her character lately

).
Ever since part 1 Sakura has been feeling subconsious feelings for Naruto little by little those feelings have been growing slowly (like a cherry blossom tree). It's not until Naruto makes the famous POL that Sakura's subconcious feelings for him grew even more. By the beginning of part 2 Kishi was obviously showing it that she felt attracted towards Naruto (ch 245 Sakura asking him if she looks more like a woman blushing at him and showing him her body so he looks at it in a sexually way if you haven't notice check the chapter). Check her profile page from the third data book Kishi is giving more ideas of Sakura's feelings for Naruto.
However I think Sakura didn't realized how much Naruto loves her she knew he likes her, but not in a serious way because she always thought of him as annoying whenever he asked her out. She wasn't subconcious or unaware of how strong his feelings for her were until 458. When Sai told her that Naruto loves her it finally hit her hard (you should check the chapter again if you haven't noticed the snitch mark on Sakura's forehead on the pannel where Sai is telling her that Naruto loves her, that snitcht mark means a reaction or realization). Once she realized the truth of how much Naruto loves her she obviously cry feeling very guilty remembering the POL he did it for her to mainly bring back Sasuke for her because he knows that she loves him. She finally finds out how much he was suffering because of his unacquire feelings for her and the burden he has been carrying on the promise for so long.
Watching her cry really shows how much she loves him because you can see it clearly how much she was suffering to find out that all this time Naruto love her for real and he has been carrying the burden of the promise in order to make her happy (and Sakura knew it was her fault he's been suffering not just the promise but for not accepting his feelings in addition she was unaware of how deep they were like I have previously mentioned). Kishi show us again how much Sakura loves Naruto when she quickly comes to the conclusion to talk to him no she's not going to stand here and let him continue to suffer because of the promise along with the reality that Sasuke was a wanted criminal and there was no salvation for him because everyone from the rookies have come to the decision to kill him.
She mades up her mind and she knew what to do. When she left Konoha Sakura had three objectives a) protect Naruto from Sasuke, b) lift the burden of the promise from him (confessing her loves she thought it was the best and most affective way to do it and c) kill Sasuke by her own hands. If you read those objectives it's clearly telling us that Sakura was doing everything for NARUTO'S SAFETY and well being there is no protecting Sasuke or confessing her love for him (she acted completely different from the Sakura from part 1). Watching her behavior change, her personality change and gaining new strong feelings for her teammate Kishi is showing us how much Sakura loves Naruto. That she has fallen in love with him for real (it's not fan girl crush compare to what she used to feel for Sasuke).
There is one problem with Sakura which I believe Kishi will finally solve it (I completely agree with catsi and ciardha on this one) in future chapters. She still has some feelings for Sasuke but it's not the present Sasuke who wants to kill everyone in Konoha, but rather the Sasuke who complimented her forehead back at part 1 on the bench scene from chapter 3. That's right she still has feelings for that Sasuke who is nothing but an illusion (an illusion that Naruto created when he transformed into Sasuke). With the release of 498 I have come to believe that Kishi is planning to solve the bench scene with Kushina's speech I believe Naruto will finally gain some confidence in his love life and he will finally take matters into his own hands. He might tell Sakura the truth that he was the one who transformed into Sasuke and complimented her forehead. If this happens we will finally see who Sakura really loves.
Edited by Gravenimage, 13 June 2010 - 05:46 PM.