Looks like they're taking inspiration from Ivan Stewart's Super Off-Road for this one. Up to 8-player local multiplayer, no mention of online though, which will really be a shame if they don't include it. They really didn't need to stick the extra 'i' in there either.
http://www.videogamer.com/news/multiplayer_racer_revealed_for_wiiware.html
http://www.videogamer.com/news/multiplayer_racer_revealed_for_wiiware.html