They did a great job keeping Iroh's appearance a secret. When he showed up, I just grinned uncontrollably until my cheeks started to hurt. Although my excitement faded the more he spoke. I guess Greg Baldwin is out of practice at imitating Mako, because he just didn't sound right here.
With Korra having to learn here how to control her anger and look for the light and peace inside her, I think this is going to end up with her taming Vaatu, convincing him and Raava to rejoin in balance.