Scene 1: a carved stone wall. In the bottom center, a mage/priest figure with a long beard is holding his arms up, in his right is some sort of scepter. To his left is a warrior in heavy armor, to his right is another warrior with what appears to be long hair. The background has many other figures, though the 3 take central importance. Most of the wall is taken up by a colossal, coiled dragon.
VO, black ground: "You should have acted."
Scene 2: close up of the left section of sn1, including what was previously off-camera. Shows several dragons spewing fire onto the cliffs while tiny people run away. Cliffs appear to have buildings carved into them, and a large rectangular structure with 4 half-arches (temple?) is also featured. Zoom into this structure.
Scene 3: close up of two dragons from previous scene, panning towards top-right. cliff-buildings clearly visible.
VO: "They're already here. The Elder Scrolls told of their return."
Scene 4: close up of secondary figures on wall - people running, cowering, looking upwards. Some are on horses. Panning right.
Scene 5: Close up of 3 primary figures, panning out an up.
VO: "Their defeat was merely a delay."
Scene 6: Another wall detail - helmeted warrior on the left, stylized Oblivion gate on the right. Slow zoom towards the gate.
VO: "Their defeat was merely delay. Til the time after Oblivion opened. "
Scene 7: close up of right side of stella. Armored men fighting. The people on the right wear pretty solid armor, slit skirt things, and horned helmets. Those on the left have shorted, full skirts with slits and segmented armor, appearing more Imperial. Area below is segmented (some sort of platform?) and littered with what appear to be bodies. Slashing swords heard in background.
VO: "When the sons of Skyrim would spill their own blood. But no-one wanted to believe."
Scene 8: Same stone as the stella, but more relief. Slow pan down, revealing claw, wing, and eventually face of dragon, coming alive from within the stone. Dragon opens eye dramatically.
VO: "Believe they even existed.And when the truth finally dawns: It dawns in fire."
Scene 9: Dragon comes alive, fully 3D, out of a cliff. Apparently not part of the stella. It stretches and breathes stylized stone 'fire' onto the stella. Little skeletal men are seen burning (think medieval manuscript illustrations of hell). Slow pan to an armored hand.
VO: "But..."
Scene 10: Armored leg, pan up.
VO: "There's one they fear."
Scene 11: Torso of an armored figure, standing in profile, a sword in his right hand and his left held in a fist in front of his head. He has a mustache, and appears to be breathing fire (or perhaps performing Thu'um). His armor appears to be Lorical Segmentata, suggesting Imperial origin. It is very similar to the Oblivion Blades armor. The fire wavers in front of him, not touching his person.
VO: "In their tongue, he's Dovahkiin"
Scene 12: Zoom in on guy's face.
VO: "Dragon Born!"
Scene 13: Skyrim logo, on black. The traditional TES theme (head in both MW and OB) plays in the background, this time with a male chanting choir.
Who are "they?"
Most obviously, dragons. However, this is not exactly a satisfactory explanation. The Tamrielic dragons, like Nafalilaargus in Redguard, were not defeated and nothing in lore suggests that they would be coming back in a dramatic, dangerous fashion. We also have no historical record of them ever terrorizing Tamriel. If they really are just strait up dragons, it could be a retcon or a gap in our lore knowledge. Other possibilities include the more metaphorical:
Tsaesci/Akaviri - they have been defeated in the past, and their coming back would be dangerous and dramatic. Dragons are also said to originate from Akavir. However, Akavir is not exactly near Skyrim. I am also unsure as to why the Akaviri (well acquainted with Dragons, Immortal Vampire Snakemen, and God-Tiger-Dragons) would be afraid of the Dragonborn. Their existence is not exactly disputed, either.
Akatosh - the Dragon Lord of Time, and Nordic Alduin, that is "World Eater." He is the destroyer of worlds, and perhaps the Nord's biggest 'enemy' (as much as a Shiva-like god can be an enemy). "They" being multiple makes this less plausible, though it could refer to his multitude of underlings (including the Jills, or time-mending lady dragons). I doubt that the Nords don't believe he existed.
The Empire - dragons are their symbol, and they were defeated, and are set to come back. The sheer amount of gravitas granted to this event makes this an unlikely explanation. Again, their existence is not disputed. However, the nature of their divine right to rule (their dragon status) probably is.
It could of course be some sort of combination of these, like an Akaviri Emperor who is mantling Talos. Or It could be someone we've never heard of before.
Who is the Dragonborn?
"Dragon Born" is used to refer to the Cyrodil Emperors, due to their being 'born' from the Alessian covenant with Akatosh. While the Septim empire has fallen, we know that at least one (that of Titus Mede) has taken its place since. The Imperial armor on the man makes Imperial origin almost certain. Dragons are also associated with Akavir and with time, so "Dragon Born" could could be Akaviri or an avatar/embodiment/child of Akatosh (like a Shezarine, but with Akatosh).
Tiber Septim (anon Talos, anon Ysmir) is the emperor most often associated with the dragon sigil. He is also the patron of empire and conquest.
His being shown strongly suggests that the player will once again take a supporting role in TESV, since the hero (the Dragon Born) is established as male and mustachio'd. It is also possible that the Dragonborn will be reincarnated in/ mantled by the player.
The latest lore on Skyrim can be found in the Aldudagga, by Michael Kirkbride.
The teaser site gives us further details on the stella. Here are my additional thoughts:
Central figure has something on the palm of his left hand. Maybe an eye? The left hand is a symbol of power in lore. I assume he is a graybeard.
The left figure is actually a mage. He holds a staff and is casting a spell.
The right figure has some sort of pole arm and a lot of tentacle hair things coming out from all over the place.
Thats definitely Akulakhan in the top-right. Next to it is both an Oblivion gate and a citadel tower above it.
There are three people, two male and one female, line up to the left of the Dragonborn, dressed in the same armor as he.
Above the Dragonborn's helm is a strange symbol. Flat at the bottom, with two curved hands coming out and a three-pronged shape in between.
