Nintendo has opened its new Smash Bros. website, where you can find the movie shown last night among other things.
The newly opened Smash Bros. Dojo features some useful info as you can see from the links on the left. I highly recommend watching the movie, and the "How this game came to be made" section is very interesting. It features an English translation of a monologue by the director explaining some of the decisions that resulted from Nintendo announcing the game.
Most interstingly, Nintendo apparently announced the game at E3 last year without informing the game's original creator (at that time, no longer an employee), Masahiro Sakurai. Apparently if they could not get him to return, they were simply going to use the same characters from Melee and simply add online functionality. However, with the return of Sakurai to the helm (a difficult decision for him about which he goes into much detail), we will now be awarded with a true Super Smash Bros. Melee sequel as recent news clearly indicates. This likely explains why the game won't be ready in time for launch.
One last bit of information from the site is that the music for the trailer was composed by Nobuo Uematsu of Final Fantasy fame. It was not suggested that he would compose for the rest of the game though. However, it was revealed that a full orchestra would be used to compose the rest of the game's music complete with "lyrics" in latin. That will certainly provide a unique aural experience.