The online player features of Ridge Racer will be a step up from your usual find-a-track-and-race fair. Instead, Namco will put up daily challenges which you (and other players in the same race team) can compete in for points. That's the Planetary League feature as hinted at in the launch trailer.
Other modes will include standard races over WiFi and ghost races over 3G. After yesterday's picture splurge, it looks like all things are go for the game at launch. Remember, the game is one of the many that will require a separate memory card for storage, but you were buying one anyway, right?