I'm delighted!
I have ever did a personal interpretation of the "story" of Super Smash Bros..
In the intro of the first Smash you can see a room (probably of a boy) and then arrives an hand (Master Hand) that pick up from a box two toys of Yoshi and Samus and then he put them on the desk; after that he prepare the desk to make a battlefield and then cowntdown to 0 with the fingers. After that the toys start do fight.
My interpretation:
Master Hand is the hand of a boy that with his fantasy makes fights his favourite characters. In the end he fights personally one of them (like many children do, I was one of them). At the end of the fighs, the character return to be a toy and the boy (Master Hand) exit from the room turning off the light.
In Melee this story is present but much more veiled (intro) but I'm sure that is the same because in the intro movie is seen a Trophy-Mario that takes life in a arena. In addition if you remember the Game Over screen from Melee there is the character that return to be a trophy...and when you finish the classic mode(or adventure, or all star) he trasforms in a trophy (the trophy you earned).
The today update is surely the most amazing that I seen because introduces a thing that I was thinking from much time: a well defined story.
[sPECULATION]In some way this dark characters that comes from the Smash universe (that existed like a sort of "limbo" from the real world and the imaginary of the boy, and now has a his own identity) wants to rule that world and than conquer other universes.
This characters are born in the Smash universe because it has become so wide that has a its own fauna (and maybe an its population), because it has been tainted from several universes. To sum up...the various Nintendo universes converges in the Smash one and everytime that something (an item, a scenario, a character...) enter in it because it creates a bridge from the two universes; in addiction the Smash universe is chronically connected with the real world (this allow us to play Smash).
This means that the original Smash univers creatures can uses this bridges to arrive in an another Nintendo universe (or maybe in the real world...). We are here to stop they!!![/sPECULATION]
Ok you are free to tell me that I'm crazy. (sorry, yesterday I've seen Donnie Darko and I've been inevitably tainted from it XD )
PS: Sorry for the bad english, I did the best I can...