The end of this season went total anime. There was so much influence from anime/Japanese monster movies and they have obviously taken inspiration from FullMetal Alchemist especially (not just in Asami's design which is openly based on Lust, but also facial expressions, certain movements etc). Which is fine by me, since that's a great work to draw from. But I can't help feeling the "battle of giants" felt somewhat out of place or underwhelming. Vaatu didn't seem to put up nearly as much of a fight as I would have expected, which was a letdown. Considering the scale of the battle between the two, there should have been a lot more collateral damage done and a lot more impressive fighting going on.
Jinora as a Deus ex Machina BETTER be explained next season. I understand she has a particularly strong connection with spirits and that's part of how she was able to highlight Raava to Korra, but I want to know more than that. Considering how much more people will be learning about spirits now that they live amongst them, I'm sure it will be possible to explain what she did, maybe even to find other people with her same power that she can form a sort of community with. Looks like she will definitely be a major player helping Korra to keep spirits and humans playing nice with each other, at least.
I hope part of next season will be Korra attempting to re-make the connection between her and her past lives. I really hope they aren't gone forever, since they were such a pivotal part of the Avatar cycle. It's the whole reason to have Avatar State, and if the Avatar can't do that anymore then she's essentially lost her trump card, plus it makes the Avatar less interesting. So on the one hand I don't really see them leaving the past lives gone forever.
On the other hand, though, I can see they really wanted to wipe the slate clean and start fresh. Fresh relations (everyone's single now, except those who were married of course), fresh start for the Water Tribes (South's independence), and fresh world (spirits&humans together). That could also mean a fresh new Avatar with no connections to anything previously. So I'm pretty torn on which way they're going to go with Korra's past lives.
Either way, they pretty much have a clean slate for next season now. To be blunt, this season was a total fucking mess and it didn't know what it wanted to do or where it wanted to go. Characters completely lost their previous experience and personalities, character growth was thrown out the window, and the story meandered a lot and relied far too much on comedy to keep viewers interested. The main character became completely unlikable and fans ended up more interested in the side characters and their cute, but ultimately pointless-to-the-plot endeavors.
They need to not repeat any of those mistakes. They need to throw out the love triangle shit completely, keep the characters in character with the experience they've gained, and pander toward the audience more in Season 3. Avatar fans seem pretty much united in what they like/don't like about creator decisions and what they'd like to see so it shouldn't be too difficult to add some of that stuff in to keep the fanbase gleeful.
Speaking of which, I did not like General Zhao showing up. My understanding was that he died in TLA and that was that. Of course, he was necessary to call Tenzin "Aang" so that Tenzin could have his little epiphany about his identity, but I was under the impression that when people die they don't go to the spirit world, or else the spirit world would be full of people. So I have to assume that the implication is he didn't die in TLA after all, which is really too bad since it seemed quite final.