Hosts can setup a varying number of stacked events (all 14 from the main game) for up to four online players to compete in. Medals are attributed according to success, but sadly are only stored by the lobby you're participating in. It would have been cool to see how many medals you've achieved throughout your whole online campaign. Sadly such features are missing.
Personal bests are saved despite playing in multiplayer, so there's no need to worry about losing a best-run because you happened to achieve it online.
Despite some solid netcode, and a great jump-in and out feel to the gameplay; there's something sparse about Vancouver 2010's multiplayer offering that will turn you off before too long. Competing is fun; but there's only so many times you can snowboard down a snowy hill before it starts to lose its appeal.