Okay, watching the first two episodes has made me more confused than ever about the fandom. I'm pretty sure that even if I hadn't read about it beforehand, I'd be able to tell from episode 2 at the latest that Katara/Aang is where the show is going. Also, Zuko...is clearly not the dramatic Sasuke type fandom seems to think he is. Whaaat.
Anyway, the show's a very interesting combination of Eastern and Western techniques and tropes. To start with, there's Katara and Aang's relationship. It's got the Western tropes of "he's not my boyfriend!!" and the way they can't stop grinning and being big dorks at each other, but it's also got the more serious, more anime-ish trope of the love interest's voice being able to call the hero back from the brink through some sort of unspecified spiritual connection, sometimes awakening new powers in the process. Heero/Relena. Squall/Rinoa. Sora/Kairi. Allen/Rinali (although both of them do this for the other, not just Rinali for Allen, which is part of why it's so awesome). I'm sure there are other examples that my limited anime/manga/video game knowledge does not cover. For the record, it's thanks to these things that I am now so severely baffled by why fandom is confused over Katara/Aang. In the first episode, it was obvious that they were instant BFF, not mother-and-son or something like that; in the second, it became pretty obvious that the show was headed somewhere romantic with them. I don't know how strongly I feel about the pairing yet, 'cause it's only been two episodes, but their interactions do make me smile.
Of course, this is partly because Aang is freaking adorable. I've been soured on Perky Messianic Boy Heroes by things like Naruto, but...Aang is just really cute. Penguins, man. Sokka is also incredibly cute--it's obvious that even though he's comic relief, there's more to him than just that. He's really dedicated to his tribe, and he seems a little unhappy that all he can do, in the midst of all this "magic," is toss a boomerang. Besides, he can occasionally be hysterical. I loved the way he repeated various synonyms for "fly" at Appa in that bored, flat voice.
Zuko and Iroh...I don't have much of an opinion on them yet (except that Iroh's comic timing is genius). But it's very clear that Zuko isn't some kind of dramatic, brooding, anime-style antihero along the lines of Sasuke (when well-developed) or Kanda (when...not-so-developed). He may later wind up intersecting with Sasuke in the way he's flawed and broken, from what I hear tell, but he's not set up in the same archetype. He's obviously the pseudo-villain who turns out to be more misguided and inept than bad and whose constant fail provides endless amusement to the viewer. From what I've read, they later develop him beyond that, and I'm looking forward to it.
Beyond all that, the one thing that really impressed me about the show at this early stage is its fantastic blocking and composition. It shines particularly in fight scenes. It takes a lot to keep me interested in fight scenes and actually able to follow them, and this show accomplishes that brilliantly and makes them extra entertaining to boot.
So yeah, when I'm feeling up to it, I'll definitely be watching more.
Edit: Also, Zuko is really shockingly gay for Aang.