The new SSX will be a heavily networked game, so you'll never feel lonely snowboarding. A presentation of the new game at EA's Gamescom press conference in Germany today focused on the game's many ways for people to compete against each other.
They didn't show any actual multiplayer. They showed socially-networked-player. One example: any time you get a high score on a mountain in the game, your data is uploaded to a server and turned into a ghost that your friends can race against. Another: Ridernet. That's an SSX take on Autolog the friend-challenge and stat-tracking system offered in last year's Need for Speed, which alerts players when their friends beat their high scores and posts chalenges to their wall (think: Facebook status updates for video games). And a third multiplayer option mentioned in Germany: "global events" that can support up to 100,000 players at a time. They didn't give many details about that, but it sounds like simultaneous score competitions. They will hopefully reveal more info soon.
EA did not show any traditional multiplayer modes in SSX. Hopefully the game will have that too.
The game is set for a January release.