This was basically a training episode, but it was still SO GOOD. All those wonderful character moments for Aang, Zuko, and Iroh. *__*
Aang learning Earthbending eee! Toph makes a really tough (and MEAN) teacher, but she's exactly what Aang needs to get TOUGH. Katara's methods are good for learning Waterbending, but Earthbending is a whole different story.
I can't blame Aang for feeling so bad about it. He was able to get into Waterbending so easily, and he's the Avatar; he's used to everything coming naturally. And as an Airbender, his attitude has always been to block, swerve, and escape. I felt so sorry for him, but he needed to be tortured to get that far. XD;
...Iroh was pretty hot in this episode too. o_o;;
Oh, and this quote... XD
Zuko: "Now I know that you think I should try to get along with my sister."
Iroh: "No, she's crazy and needs to be brought down. :/"
Or something like that. Anyway, Zuko learning to bend lightning. So the theory that lightning is a higher form of Firebending is correct. And Zuko isn't ready at all, IMO. He's so emotionally unstable, it seems dangerous for him to even try.
Which brings me back to that last scene. D: You could really feel Zuko's frustration. ARRRGGGHH. Makes me want to cry too. I just wonder what it's going to take for him to get over this. Poor Zuko, he's come so far but still has a long way to go.
As for other characters....they need to stop making Sokka be the comic relief all the time. D: He's becoming pathetic. Though, some of the moments when he was stuck in the crack ("Now come back, boomerang") were very amusing. XD;
*sigh* No more new episodes until July 14th. THAT SUCKS. DX
EDIT: You know, with Zuko's comment of "This sounds like Avatar stuff," I think this episode really shows that Iroh would be Aang's ideal Firebending teacher. Iroh is already familiar with the different styles that go into the other bending arts that Aang would know by the time he gets to fire, and he'd definetely be able to show Aang how to control fire, like Jeong Jeong said.
Zuko, on the other hand, is still learning himself. I don't think he'd be in the frame of mind to teach someone else anytime soon. But if he and Iroh join up with Aang's group later, then he'll get a chance to observe Airbending, Waterbending, and Earthbending up close. And like Iroh said, if he can Firebend by learning from those other styles, then he'd have moves that Azula doesn't.
So to sum things up, I hope Iroh survives until the next season. D: But then, he can survive a lightning bolt to the chest, so maybe it is likely that he will.