On our (pretty crappy) broadband connection, the game played really smoothly. It supports 14 players online - we got 10 going, and noticed nothing but total responsiveness. The same blocking, swerving, sliding and boosting that are the cornerstones of the offline game showed their true importance playing against human opponents.
The game features a very basic lobby (you can send simple pre-set text messages while you wait; your main option is to confirm that you're ready to roll.) An interesting mode we didn't get to try is the team battle - it ranks the overall performance of the entire team to determine the winner. You can also choose to either allow or ban modified cars in online matches. Our takeaway is simply that online performance is nice and smooth, and that's what we were most worried about.
We also got to try the Sixaxis tilt control for steering, but that was a total disaster. It's going to take a lot of practice to make the switch - but Ridge Racer 7 plays perfectly with traditional controls, so we're not really complaining.
Ridge Racer 7 is almost here - we have final review code, in fact - so there's not a great deal more to say: we've been playing it for months and we're ready to put it through the paces and see if it lives up to the series' high-speed legacy.