I watched the first two episodes again (yep, it's that good), and I had a couple more thoughts. One, the pro-bending folks are surprisingly blase about discovering the Avatar is on their team. I mean, the Avatar's kind of the most important person in the world, this deeply sacred figure. It's kinda like having the Dalai Lama or the Pope join a sports team. Yet the sports folks merely had a few moments of surprise and then just rolled with it. That seemed like something got glossed over for the sake of pacing.
Also, one thing that concerns me a bit is that so far, all the bad guys seem to be male. I know Azula, Mai, and Ty Lee are tough acts to follow, but it's just not an Avatar-verse show without awesome, kickass young ladies on both sides.
And I guess that "roll eyes skyward, then give a world-weary sigh" business is pretty clearly going to be Tenzin's "thing," but what's impressive is that the animators have him do it a bit differently each time. I love the attention to detail. Joaquim Dos Santos is probably the best animation director in television (though credit should also be given to his co-director here, Ki Hyun Ryu), and it's great to see his work again.