Just managed to watch the first two episodes. Pretty good so far. I definitely like Tenzin's kids. They're hilarious. So far, though, we haven't gotten too much info on the main conflict of the series. I'm hoping they find a way to make it feel as epic as TLA. After you save the world from Fire Nation oppression after a 100-year war, fighting some anti-bending protesters seems a little lame. Obviously, though, we don't have enough information yet to make that kind of judgment.
One thing I really would like to see, though, are some flashbacks or something to the original characters. As much as I appreciate this show's ability to exist on its own, I couldn't help but miss the original crew.