Some new info!
In our short time with the game, it's very clear: Mario Kart DS is awesome. Awesome. The classic old-school karting action works extraordinarily well on the Nintendo DS platform.
How on-line races are decided:The game, classic Mario Kart action, runs at an incredibly smooth 60 frames per second rate, and gets pretty fast and intense especially in the game's unlockable 150 CC mode.
The Internet play is limited to simple four player racing matches, and players "vote" on which tracks to race on during the connection; the winning selection (the highest number of votes) will be the track everyone races on. The computer will choose the track from the voted list if there's a tie
What about Lag??
the article:The internet connection was admittedly a bit temperamental, with some lag issues and situations where players were randomly dropped from the action. But since the room was filled with dozens of players partaking in the Wi-Fi play, the lag and connection drops could have been attributed to the jammed wireless traffic in the area.