If Zutara actually went canon, I would have found the relationship very interesting, because they bend the opposite elements, Fire and Water, which I think is cool. And, they have a really cute moment together (not really) where Zuko put Katara's necklace in front of her neck, and it looked so romantic!!! Their relationship could have been a love hate kind. Maybe Zutara would have become canon, if they changed that one episode where they visit the Fortune Teller in Season 1, Episode 14. Katara's fortune was that she was going to marry a strong bender who could have been Zuko, if she didn't realize it was Aang towards the end of the episode. Even though Aang would have been heart broken, he'll probably understand that Zuko and Katara love each other, and Aang finds it in himself to fall in love with another girl whom he was meant to be with from the start. :)