I found something on YouTube. I thought it was a little more elaborate from what you guys were saying.
There's a sense of nostalgia you get with those intros. They didn't have them in Melee and it made no sense, especially since they're not that tough to do. Brawl's character intros are going to be a lot more detailed judging from the clip of Snake (if indeed that is an intro).
Somewhat off-topic...I've heard rumors that they might be releasing SSB 64 on the VC a few weeks before Brawl comes out. They did it right before Metroid was released, so hopefully they'll do the same for Smash. It'd be nice to be able to play all three games on the same console.
My fingers are crossed and I really hope this actually happens.