That was a really good finale.
I'm disappointed Amon was just a blood bender who had nothing to do with the Spirits, though. I really wanted to see the Spirit World and Koh again. They did surprise me because once Tarrlok was revealed to not be Amon and he was too young to be Yakkone, I never considered there would be another member of that family involved.
I would have appreciated a more specific explanation of how blood bending can become energy bending (which is something I recall theorizing a few days ago!).
I really hope Iroh is a regular character now. He was so bad ass! Fall out an airplane? Oh no problem! Of course, in the old show, weren't fire-benders only able to fire-jet-fly under Sozin's Comet...?
I was hoping that Season Two would have Korra only as an airbender on a spiritual quest to unlock her old powers. They should have run with that. Again, we could have seen the Spirit World, and she could try to connect with Aang. So that ending was uplifting and cool but also rushed.
We finally saw Bumi! Hope to see more of him next year.
I thought it was really odd that Tenzin's family was captured off screen after spending an entire episode making sure they escape. I thought they were imposters meant to lure Korra to the stage. That was some convenient/poor plotting.
I really enjoyed seeing a big naval / aerial battle with bending use intermixed. I would have liked to have seen Korra being more of a contribution to the battle though, saving more battleships from torpedoes and so forth.
I loved the scene where Tarrlok kills himself and Amon. It was a great end to their story. Amon was actually being nice and hopeful while his brother quietly kills them both behind his back. Great stuff. He better not survive the explosion!