In all the thousands of posts in both this thread and the Kataang/Zutara battlefield threa, I have never come across anything that I have ever disagreed with more (okay, mabye I have disagreed with some things more, but this is still pretty ridiculous).
We've all said this to the Zutarians, now we have to say this to doubting Kataangers: You have to be blind not to pick up on the fact that Katara has feelings for Aang long prior to the finale. The simple difference between Aang and Katara is that Katara has managed to get her head around the fact that they are in the middle of a war, and when saving the world and romancing with Aang clash with each-other, the romance takes second place to saving the world. That is what the Guru meant about Aang learning how to let go: he needed to understand (as Katara did) that he had to ignore his own personal needs in order to devote his entire being to the task he needed to fulfill.
Perhaps it would be easy to simply compare the two concepts of Katara and see which one matches the Katara that we have seen developed over the course of the series:
First there is a Katara who chooses to ignore her own feelings in order to do what she knows is right (letting go of her growing love for Aang to concentrate on the task at hand).
Or there is a Katara who feigns false feelings for Aang in order to encourage him to remain interested in her so that if he wins she can pretend to fall in love with him to get the "fame of being the girlfriend of the avatar".
Which one of those options sounds more like Katara to you?