What I'm extremely stoked for in terms of the soundtrack is the ability to customize it with your own music that you have saved to your system. The music will even morph to the actions in the game, like skipping while grinding or fading and then slamming back down with a heavy jump or trick. I can't wait to play SSX with The Mars Volta, Dethklok, Red Hot Chili Peppers, and my own music that I make in the background and have it actually interact with the game. That is something more games need to do. But from the looks of the pre-rendered songs, we should be in for a real treat.
I love that they made it so we can use our own soundtracks and that it mixes the songs in the game. I will definitely be using quite a few songs that were in SSX3 as I loved that soundtrack. I think there will probably be a few good songs in the game already too. I hope there's an option of mixing in-game stuff with custom lists.