Wow, those are some insane percentages, considering it was ONE PANEL. No offense, but I think you're really jumping to conclusions. It's not like she was happy to be in love with Sasuke. It's not like she's come to terms with her love for him, leaving it up to Naruto to bring him back. In fact, the more I analyze it, the more I think this could help our pairing in the future. Think about it, the love letter ninja served no purpose other than to remind her of her love for Sasuke, a love she LAMENTS. The fact of the matter is that she's distressed about being in love with Sasuke. If the point of this scene is to remind us that she loves Sasuke, then don't you think Kishi is being a little redundant? It seems obvious to me that this isn't a stand-alone scene. Sakura will have to finally resolve these feelings that are distressing her, feelings that she clearly hasn't come to terms with.
I'd also like to point out something interesting I've noticed throughout the manga. Everytime we see SS and NH take a step forward, NS takes ten steps forward shortly afterwards. Observe:
1.) Sakura confesses her love to Sasuke. Sasuke thanks her, but leaves anyway.

Naruto then promises to bring him back, and Sakura realizes Naruto understands her more then anyone else.

2.) Sakura punches Sai out after badmouthing Sasuke.

Yamato later comments that Sakura's feelings for Naruto are more than that of friendship.

3.) Hinata confesses her love to Naruto. Pain 'kills' her, and Naruto goes berserk.

Naruto comes back and Sakura gives Naruto the sexiest hug in the series thus far.

4.) Sakura 'fakes' a confession to Naruto. Sai tells him she wants to kill Sasuke because she loves him.

Naruto saves Sakura from Sasuke in a very symbolic scene (see Minato's rescue of Kushina).

5.) Sakura thinks of Sasuke after reflecting on someone else she likes.

[insert best NaruSaku moment ever here]