Okay, boy was I wrong! O.o Well, okay, I sooorta called the stage, but really I had doubted it too much. But I'm lovin' this update. 4 vids and a new stage. freakin' sweet. BTW, I'm a big fan of Snake in Brawl for those who can't figure that out. :P This is gonna be sweet.
I think the video of Snake Joining Brawl is made up of three types of video. One type is the video where they're talking about Mario. I believe tha is from the campain if you play through as Snake. The Gameplay is obviously from in game fotage, and the Video of Snake and Mario's battle on his new stage is from the battle where you unlock Snake. At least that's what I think.