First, to ShortFuse, he is a DigiPen student. I was wrong in my original post; this event did not take place on DigiPen's campus, but rather at the Nintendo HQ (which is right next door) in a room called "Cafe Mario". Many DigiPen students didn't even know about this, I imagine. My friend has contacts in Nintendo's HQ, though, so he heard about it and was invited in by a Nintendo employee.
Stormkeeper, you are right on track. The nerf, as I've tried to imply, is a nerf from the Fox we knew in Melee. It very well might end up not being a nerf at all, but rather just force new Fox players to adapt to a different playstyle. This follows exactly from the thought that Brawl, as a whole, should be very similar to Melee in terms of character design. Why would we want this? Aren't we buying Brawl because we want to play a new game, not a 6 year old game?
As for the Sonic win screen music, I will ask him about it. Unfortunately, I don't think he's played much Sonic, so he will likely not be able to place where it's from in the old Sonic games and instead just say "it's a guitar riff" or something. But yes, I will ask him.
Since you all are asking, here's some other stuff he said to me. He was also a big Link player in Melee. He feels the up B hits a fair bit weaker than its Melee counterpart, but the gale boomerang creates far more problems on return than the normal boomerang.
Ike's final smash is a point blank (Street Fighter term meaning immediate strike, directly next to an opponent) attack which sends the guy "way up (I mean, WAY UP there)" and Ike follows him and does a nice combo before smashing him away.
Ike plays "nothing like Marth or Roy", even though his forward smash is an arc-like attack similar to Marth (he doesn't know the hit properties of it yet).
Sonic "is enjoyable", but he wants to play more with a classic controller. All 3 of his B moves (not up B) are spin attacks. Forward B homes in on the nearest player. The other two were covered on the Smash Dojo.
Metaknight's final smash is also PB, and mimics a Hibiki super from CvS2 (the screen goes dark, Metaknight does a bunch of samurai-like sword slashes, and then he smashes him away).
You have to be grounded to use the Final Smash item (at least, of all the characters in the demo). He said he saw many players get the final smash in the air, but weren't allowed to land to use it.
The 8-bit spring from old Mario games is an item.