FIRST: the forest dungeon.
I think the door at the beginning of the trailer is the entrance. The three-leaf symbol in the corners appears over a couple other doors as well. Also, the pillars around the door look similar to the ones around that other puzzle door in the tightrope room.
The three-leaf symbol is a little harder to see here in the image below, but if you watch the video, it's there. This room also has a very distinctive door that we've seen before.
That last one is in the room with the scorpion boss from the demo. The design on top of the door is different, but the door is exactly the same. The same door also appears in the Stalfos room, so that might be a miniboss. Also notice that in all of these screenshots that are from the GDC trailer Link has six hearts. The only other scene in which he has six hearts is the one with the spider, just after the first door scene. If you scroll back up and look at the scene with the beetle flying around, you'll see a large white mushroom next to the door that looks very similar to the plant life in this spider scene.
Link also uses the beetle in two of these scenes, making it difficult to decide if it's acquired in this dungeon or the fire dungeon (more on that later). So so far, the forest dungeon includes:
-the triple-leaf appears to be its main symbol
-recurring pillars
-recurring inlaid arch designs
-general stone structure with some overgrowth and white (possibly frozen? or spore-covered?) foliage
-skulltulas - or spiders of equivalent size if they can't be classified as such
-keese (flying around in the scene with "skull kid")
-green bokoblins (on tightropes!)
-a puzzle door just like the one that appears later on in the trailer with the dragon key, but this one seems to require a different-shaped key
-recurring flower-design doors
-dungeon item: possibly the beetle
-miniboss: possibly the Stalfos
-boss: Scorpion
That's the one I know the most about so far, which would make sense if it's the first dungeon, or very close to the beginning of the game. I mean, before ST released, they showed demos of the first dungeon and boss.
SECOND: the fire dungeon
This one's quite a bit easier to distinguish: all the scenes with lava are in this dungeon! This includes a few from the GDC trailer as well as some from the E3 trailer. The only thing that required symbol analysis here is the puzzle door.
I also noticed that the design around the yellow circle in the Lizalfos room (wavy lines with dots) is also found on the pincers of the beetle, which was used in this dungeon in the E3 trailer. This makes me want to think that it should be associated with the fire dungeon, but then how does Link have it in the forest dungeon? That will remain a mystery for now, unless someone else has some insight. The bow is also used in the fire dungeon in the E3 dungeon, so maybe that's this dungeon's item.
I had assumed the four-armed Stalfos is in the fire dungeon, just from the red tint of the scene, but Link has nine hearts, while every other scene in the fire dungeon has seven.
So far the fire dungeon contains:
-flame symbol
-lava, floating rocks/rock structures
-Fire Toadpoli
-Fire Snail
-Bokoblin (red/orange)
-Fire Keese
-Lizalfos
-Gohdan-like designs on walls, among other Eastern or Aztec sculptures
-Puzzle door with dragon key
-item: either bow or beetle
THIRD: unknown
It could be the mechanical dungeon if four heart pieces were collected before it was shown in the trailer, but for now I'll classify that as the fourth.
FOURTH: mechanical dungeon
There are only two scenes in this dungeon, both sharing brick walls, yellow plus designs, a strange circle design, and mechanical enemies.
I'm not sure about these two:
I was almost certain the Stalfos Warrior was in the fire dungeon, but I couldn't find any symbols or anything to back that up, and Link has nine hearts in this scene as well, rather than the seven he has in other fire dungeon scenes. I wish I could get a closer look at that door without the bars. For now, I'll throw him in with the mechanical dungeon just because of the hearts.
Finally, the boss fight. Link uses the whip and has nine hearts. The door look like it has a gear symbol on it, which could connect it to the mechanical dungeon, but everything else is completely different.
So the mechanical dungeon contains:
-recurring yellow plus design
-recurring circle design
-grates
-Different types of Mechat
-Mechanical Totem Poles
-miniboss: Stalfos Warrior?
-boss: Mecha Shiva?
-item: whip?
Aside from the title screens and the bamboo-cutting mini-game, this leaves two scenes that I couldn't place in any one dungeon.
The first unique scene is the one with the Spear Moblin. Link has nine hearts, and this is the only time the lyre is shown. The white ground and foliage almost looks similar to that of the spider room, but these other details along with the lack of man-made structure anywhere in the scene lead me to believe that this is a completely different area, possibly not inside a dungeon at all.
Next, there's the desert scene with the Electric Rollobite. Link also has nine hearts here, but the locale is completely different. This one is obviously not inside a dungeon, unless it's an extremely open dungeon.
