Anyway, spoilers for the Secret of the Fire are ahead. They show a short 5 min preview for the movie.
Zuko and Iroh make it to Ba Sing Se. They are at some refugee camp (from the looks of it). And guess who's there? Jet (I thought we saw the last of him). Jet apprently, went to Ba Sing Se for atonement or something like that. Iroh, Zuko, and Jet are talking to each other over tea. Jet tells Iroh and Zuko about he came there because he wanted atone or something like that, and he has done some bad things. Iroh tells Jet that he believes in second chances and looks over to Zuko when saying this (obviously saying it more to Zuko).
Scene changes to Aang, Katara, Sokka, and Toph. They are going to go into Ba Sing Se from the Serpent's Path. Who else shows up? Suki! (remeber the Kyoshi village leader said Suki and the others went ot Ba Sing Se) Also the couple that was in Zuko Alone (in the beginning when Zuko was going to steal food from that guy, but then he sees the pregenat wife.) So then Katara does the Moses spilting the sea thing and then they start traveling under water in an air bubble made by Aang. Momo jumps out of the bubble and it chasing some fish. A enormous sea serpent thing comes up and scares Momo back into the bubble. The serpent breaks the bubble and then they start to drown, but Toph raises the ground, so they are above the water, no one's hurt. Sokka says "I think I found out why it's called the Serpent's Path" and then...it ends!
Aaron Ehasz showed this little slide-show thing. It was so cool. It was a "shippers" slide-show. Then he was telling about what shippers were and stuff. They basically showed pictures of the two people and and + sign w/ a heart struck by an arrow and the name of the ship at the top. They had almost every pairing (no guyXguy and girlXgirl pairings). The sickest ship they had was Blue Sprirt X Azula (this guy after it quieted down yelled "What's wrong with you!" and everyone was cracking up).
So first had 'Harutara'. They had 'Momiyuki' (Momo X Miyuki), 'Foamzula' Foaming guy X Azula, Foamtara, Foamsuki, Yuekka, Sukka, and so many others. Lot of them were crack ships actually. For the last two it was Kataang & Zutara.
I just remember some other things. Giancarlo Volpe showed this little tour of Ba Sing Se. It was some shots of the city. It looks a lot like Omashu, but (as Volpe put it) Omashu is more of a cake and Ba Sing Se is flat. The inside looks a lot more crowded by houses than Omashu. There was also some kind of crop fields by the inner wall. There are two walls completely surrounding the city. You can get to the city in 3 ways. You can go by this train thing (looks similar to a trolley;probably uses earthbending to move it) or by a ferry, and for adventurous ones, by the the Serpent's Path.
And something, that I hope to god was a joke, was told. Zuko goes on a date. They even show him all dressed up (he can part his hair now). They said they would show who his date was. They did...but her face was blurred out. It kinda looked like Katara, but she was wearing a green dress, not too fancy, and she had longs braids on both sides of her hair (sort of Katara's length). She was tan and her hair color was similar to Katara's but I don't know...(please let it be Katara disguised).
So in the trailer it showed Azula, Ty Lee, and Mai plotting. Then there's this general looking guy that says we're doomed to Aang (he was looking through a telescope thing) and this other fire nation general appears says "they can't stop us now". Aang is talking to someone (think it was Katara) and says I was looking for Appa, but I saw something else.
Byran and Mike made this behind the scenes thing espically for Comic-Con and it shows a normal day for them. At the part where they were doing character design, it showed an Appa sketch, but he was all torn up looking! Poor Appa. The behind the scene thing was pretty funny. Bryan was driving in a car and was saying it was important for their lead role to be a vegetarian and...he drives up to a in-and-out and orders two double-doubles. It also showed their office...it was scary and so messy. And one clip showed a Zuko and Sokka action figure fighting each other then this big doll glomps then both. It was very funny. Showed Mike editing scenes saying to move a rock higher in a scene and moving the ground up higher (was boring) and at the bottom it was flashing EXCITING!!!
some other pairings they showed in the shipper-slide show was 'TyLokka', 'Maizu', 'Tokka', 'Taang', 'Junoh', and remeber the twin old ladies that were w/ Azula in the premeire; paired them w/ Iroh so it was someone more his age: 'Loiroh', 'Liroh', and the threesome 'Lirohlo'.
Last thing for now. When everyone was exiting, they showed some fan art by Isaia, Booter-Freak, and others! I'll try to find the links! Hope this made you all happier.