Interesting. Though it doesn't cover all lose ends. Right now these are the lose ends I can think of:
- Koh the Face Stealer is probably going to make his return ("We'll meet again", and I remember I read something about some announcment the writers made, I am not sure though).
- Jeong Jeong is suspected to return again (Aang: "Yeah, like we'll ever run into Jeong Jeong again", kind of obvious )
- King Bumi
- The girl from the episode "Bato of the Water Tribe" (the one with that big beast she rides on) is shown fighting in the finale trailer, so she'll be back
- Bloodbending (They didn't introduced it for nothing)
- The White Lotus is obviously going to do something. Known members of the White Lotus are Iroh and that swordsguy that trained Sokka (not a 100% sure, but pretty sure )
- We're going to know a little more about Ursa probably.
And this all has to happen in just 6 episodes now. I am sure this is going to be spectacular