Okay, I need to let loose some steam. New episode spoilers ahead!
Aang's death makes so much sense now. If he didn't die, he'd have been pretty old when all this happened. If he died later, Korra would have been too young to handle this. Also, there's something to be said for a water bender being the Avatar the second time around, when it was a fire bender the first.
The Lion Turtle giving Aang energy bending isn't a cheap plot device now! It's part of the lore of the Lion Turtle! YES! THANK YOU! (Also, did we see that Lion Turtle again at the end of the episode?)
The Avatar's origins are a lot more humble than I expected. Who knew that stealing fire bending to get some food for people could set you on a path to becoming the physical embodiment of balance?
Unalaq must know about Vaatu; that explains why he emerged from the portal. Is he going to bond with Vaatu, like how Wan bonded with Raava? If not, will Korra be the last Avatar? Is the Avatar's existence throwing the world out of balance, because there is not a "dark avatar" to counter it? How did Unalaq even learn about all of this anyway?
Wan's death scene was really sad. I actually felt sad. And I knew him for less than an hour. Great stuff.
The art style was beautiful. Loved it.
The statue that Jinora saw was of Wan and Raava.
Wait, so the fire sages were raising air bison during the hundred year war? That explains why they still exist, but... why did they do that? I know that originally, there was resistance to the fire lord, but by Aang's time, most of them were pretty subservient. I guess it had just become an ingrained habit (also, why would you kill off a bunch of creatures that probably like you...). Did they sneak them away, or ask for them?