Well, only six-episodes left of Book 2: Earth. This season's storyline is much more
solid than Book 1: Water was just Aang's realization of his destiny's
weight and heading to the North Pole to find a Waterbendering teacher.
There were other plots too, Zuko's quest to capture the Avatar, and
Zhao besieging the Nothern Water Tribe. The strike against the North
only lasted three episodes; I think the plot was more of a way to give
first season an explosive climax instead of wrapping up the season???s
plot. In Book 2: Earth, Aang's quest to find an Earthbending master was
put to rest in the first quarter so that left the need and room for
more ambitious storylines. We have the solar eclipse and the Ba Sing Se
dystopia subplots concluding, other bits I see happening???

-Iroh being recognized as the Dragon of the West. He committed the
greatest assault against Ba Sing Se ever known. SOMEONE is going to
realize it???s him??? And when this happens being pursued by Azula will
pale in comparison, this is the city Long Feng resides in.

-Jet???s redemption. His redemption and second chance I see as more
likely happening than Zuko???s. Sorry, I???m not exactly in the camp of
???Zuko and Iroh seek the Avatar and Co.???s help??? or vise versa leading to
Zuko becoming a fellow Avatard of the Aang Gang.

-Zuko vs. Aang. I smell the ultimate showdown between these two here,
perhaps even the last. Well??? that is if Zuko doesn???t become Fire Lord
by next season???s turn. What? The rivalry between these two is one of
Avatar???s foundations and important drives. It???s Aang vs. Zuko, Avatar
vs. Fire Lord.

-Appa???s return. From what I???ve heard he???s ever the ferocious beast.

-Toph being subdued and taken away by Xin Fu and Master Yu. A dashing
rescue to reclaim the runaway heiress; what brave souls will her
saviors??? Could Jet assist the Aang Gang in rescuing their little
sister?

-Azula is cooking up something; you think the DRILL was BAD?? And I hear daddy dearest footsteps not too far behind.

-There-is more to Long Feng than simply being the man behind the man. This is
a villain who puts both Zhao AND Azula to shame. I swear he???s done more
than merely create a dystopia and obstacles our heroes need to
overcome??? Villains as dangerous as him have personally ties to main
characters. Is it possible Long Feng met Iroh at the battle of Ba Sing
Se? Even??? killed his son???

-Toph is somehow tied to Iroh, maybe even Zuko. They
met in episode 29 ???The Chase,??? and shared wisdom and tea together. Iroh
even comments ???you sound like my nephew,??? this could mark something for
Zuko and Toph in the future. Toph and Iroh wasn???t a one-time deal for
???The Chase.??? Toph speaks of Iroh when at the wall of Ba Sing Se, meaing
she hasn???t forgotten her friend, and Sokka shoots her a look because of
her comment, possibly implying something. They have also been chased by
the same men Master Yu and Xin Fu. Where Toph and Iroh will lead to I
have no idea.

-More on Lu Ten will be revealed, this has been
confirmed. There is the theory Iroh journeyed to the Spirit World to
find his son, and that Koh the shape-shifter has stolen Lu Ten???s face.
Whether this holds true or not, I???m anxiously awaiting Koh and Lu Ten,
and Iroh???s journey!!

Season 1 was more of an introduction, it kinda set the tone (like you said, Aang realizing his destination thing). I loved some of the episodes in season 1, and only The Cave of Two Lovers and Zuko Alone in season 2 though.

Geez, this isn't just for me! C'mon people, post your theories of what's going to happen for the rest of Book 2: Earth here! Will Zuko join the Aang Gang? Will Ba Sing Se attack the Fire Nation at their weakest? Will Aang realize assaulting the Fire Nation is wrong?

Ooh, love the theory! Hope you're right!

Well that answers my question of what Bumi's plan might be. However, I'm a bit sceptical...

What about Appa though? He's the last Air Bison known in the world. If the whole brainwashing thing could work on other creatures besides humans... that could prove to be some bad omens right there...

What really interest me is the solar eclipse. Once the Earth Kingdom hears this information, isn't it possible that they attack the Fire Nation with no mercy and could anhilate them all? Living your whole life in a war won't make you a nice person now, especially to the ones you are fighting.

I see definate problems for the gang involving the brainwashing. Who knows how many of them they might get. One thing to mention though is that Toph will be immune to the brainwashing because of her blindness.

About the people recognizing Iroh: With the exception of the guards, Dai Lee, and their commanders, no one knows about the war, much less who was attacking it. Back then, Iroh was the famous Dragon of the West. 3 years later, he's serving tea. Considering he actually got into the city, I doubt anyone's going to recognize him unless he firebends or the Captain of the Outer Wall shows up. (You know, the guy Iroh got the knife from in Zuko Alone?)