So, basically a Subspace Emissary trailer, some old stuff and some interesting new stuff flashed onscreen. And I feel the intense need to disect it all one piece at a time! Here we go!!
* Already seen on website
** Already seen on the demo from GameTrailers
> Opening scene of the Halberd dropping dark matter upon the stadium where Mario and Kirby are. Primids form as the Subspace Emissary's logo appears.*
> Mario's surprised look from when the Halberd first arrives.*
> Pit looking up after landing on a grass field.**
> Fox using his reflector to reflect a large engery blast.*
> Mario, Peach, Zelda and Kirby strike an action pose in the stadium.*
> Primids begin forming from dark matter in the forest.
> The Subspace Minister flies away from the stadium.*
> Pit in Skyworld looks shocked at the Halberd releasing dark matter.**
> Cut to a bunch of Primids in an unknown metalic chamber. Some are wielding beam swords and ray guns.
> Mario in gamplay fighting Primids in the stadium. Cut to Zelda also attacking, using her Foward+B.**
> Rayquaza emerges from water and roars.*
> Near the pond, Diddy Kong and Fox jump out of the way of a trophy-transforming blast coming from Bowser.
> Peach is lying defenseless, unrescued, after the Petey Pirahna fight (as opposed to Zelda who we've seen)
> Mario is sent flying away by a cannonball. Zelda and Kirby look surprised as the subspace bomb ticks.*
> TIME FOR ACT II!
> Open to some grassy ruins with a mountain in the background.
> Cut to some gameplay here where Ike can be seen battling some Roaders and ROBs. He uses his Up+B Aether attack.
> Cut to another different set of ruins in a snowy wasteland.
> Cut to a end-level door inside some arched ruins/dungeon. It is guarded by two red spikey enemies encircling it.
> Link is seen briefly in a fiery lava world.
> Donkey Kong beats his chest in a forest.*
> In gamplay, Donkey Kong uses his Down+B attack to smash some Goombas into overhead Koopas.**
> Lucas does either a dash attack or forward aerial into a row of Bytans in a underground sewer-like place. He then uses his foward smash
baseball bat attack (bye bye Ness!) on one.
> Diddy Kong and Fox take on some Goombas and Koopas near a jugle waterfall. Diddy uses some sort of running kick attack.
> Cut a mine shaft with a mine cart skidding rapidly down it, knocking out bizarre green and yellow music note-like enemies. No playable characters are onscreen.
> Link and Yoshi take on a floating tentacle monster in a large cave filled with glowing blue mushrooms.
> Meta Knight and the Ice Climbers are seen battling weird translucent humanoids on a moving platform in an ice cave filled with giant ice crystals.
> An interesting empty side scrolling segment of a meadow pans upward to show a huge open vista with a rainbow.
> Bowser roars near the lake.
> Wario shoots the trophy-transformation gun in the stadium.**
> The Koopa and Goomba-driven cart full of bananas fires three bullet bills in the judgle.*
> At the lake, Rayquaza shoots out an energy blast.*
> Peach does his somewhat redone Forward+B attack on an enemy in some sky ruins.**
> Samus fires off her new Smash Forward+B super missile attack inside an ancient stone corridor.
> Pikachu does its forward smash in a metallic passageway.
> Petey Pirahna clashes two cages holding Peach and Zelda together and then roars at Kirby.*
> The Halberd is seen in Skyworld firing a large volley of shots at an Arwing.**
> The Subspace Bomb in the stadium opens by two ROBs.*
> Fox ejects from his crashed arwing high into the sky.*
> The stadium Subspace Bomb explodes and emcompasses the stadium.*
> The Subspace Emissary logo appears again, followed by
http://www.smashbros.com/