[Update: I swapped the video with a better one of the same event provided by deityofanime. Thanks!]
I'm pretty sure that this is footage taken from Masahiro Sakurai's Nintendo full presentation on Kid Icarus: Uprising (all of which can be seen here), but his show was over a half hour long. I figured you might have missed some of the gamplay footage that was hidden in there.
There was no sound to the video, so I uploaded some classic Kid Icarus music for you you to play along with. That's not all though! The footage is also a little blurry, and because Sakurai is talking while he's playing, he sort of sucks at the game.
All problems aside, for a near-life long Kid Icarus fan like myself, this video was still more than worth watching. I hope you enjoy it as much as I did.