I've actually read interviews with the creators where they state that Korra would not have an over-arching storyline like Avatar. Unfortunate, but they've been doing a pretty good job with the new format so far. The new origin story for the Avatar is awesome, I agree that the old origin of bending was probably just about mastering the elements, not actually having the ability to bend. And remember, technically only Water Benders learned from the Spirits, everyone else learned from animals (maybe Spirity animals, but still animals).

I think my biggest gripe with the show is the romantic entanglements, which is annoying because they didn't start off bad. I also hope we get to see more of ‘Team Avatar’, I feel like we didn’t get enough of them as a group in these 2 books.

I also love the new mythology, but the Giant Turtles seem to conflict with man learning to bend water from the moon spirit, fire from dragons, et cetera, but this could be explained saying they were given the gift of bending by the Turtle spirits and then they learned to master their bending by observance of the said counterparts, except that the spirits were pretty much gone from the world when man started bending permanently.

I have to nerd-out over here because I deleted my facebook. Ahem.
Stylistically, Legend of Korra has been even better than the original. Humor, it's just as good; it still goes from seriousness to a small joke that makes you giggle and then right back to serious without ever missing a beat: something that when I think about it, is really weird and amazing they can pull off. Characters, while no one strikes me as sympathetic and as tragic as Zuko (all though at times Asami comes close, or even Tarlok and Noatak at the end of season 1), they are all still great. My only concern is that we are now through with the second season and there is still has no over-arching storyline aside from Korra's relationships. And although I was very happy with its conclusion, I was hoping the Dark Avatar arch would continue on into next season. As it is, each season is a new problem which ultimately has been resolved by its end. I'm enjoying the journey, but I wish there was a destination in sight.

Hey, aren't you that guy that lives in the room across from me?