Taken from the European Mario Kart Website:

With Mario Kart Wii’s launch date of 11 April fast approaching, Wii owners are gearing up for a racing experience unrivalled by any other in the kart racing series. While the game introduces a slew of new features across the board, perhaps most eagerly awaited are its online options, which take the Nintendo Wi-Fi Connection action found in Mario Kart DS to a whole new level.

In Mario Kart Wii you can go online via Nintendo Wi-Fi Connection by yourself or together with a friend playing on the same Wii console, and let the games begin! You can directly jump into online races with random players Worldwide, or opt for Continental if you prefer a challenge closer to home.

Then you will be placed in a new group of people looking for a match, or you will join an existing group. When the latter happens you will become a spectator of that group’s race currently in progress, as you wait for your turn to hit the track. With up to 12 players being able to battle or race on the circuits of the Mushroom Kingdom simultaneously, Mario Kart Wii is set to provide the biggest challenge in the series to date!

After swapping Friend Codes with other players, you will also be able to see how many of your mates are online, and choose to Create a Room or select Join Friend to gather in a room with your friends before you start your engines.

Once inside a room, the globe familiar from the Forecast Channel will highlight the location of all players present. This is where you can text chat with your friends by making a selection from dozens of predefined messages, letting you suggest exactly which kind of race you want to play: from Battle to Grand Prix, and from Team play to your circuit of choice. The Host then decides the race settings, but the track selection is based on the votes of all players combined.

Mario Kart Wii also allows you to install the Mario Kart Channel on your Wii console. This Channel lets you check up on a host of options without the need of inserting the Mario Kart Wii disc into your system.

The Ranking option lets you see your statistics for each track and compare your results to those of your Friends and other players worldwide, represented by their Miis. You’ll have the option of racing against the Ghosts of the best players, or improving your results gradually by taking on the Ghosts of rivals whose times are only slightly better than yours. Players can choose whether they want to share their Time Trial Ghosts with the rest of the world, allowing you to match your skills against the cream of the crop whenever you want.

Another all-new feature of this Channel are the Competitions, where Nintendo will on a regular basis invite players to speedy challenges similar to the Missions of Mario Kart DS. The Channel also allows you to check your ranking in running Competitions as well as Time Trials. You can also go here to register Friends and see if any of them are currently online.

There’s much more Mario Kart Wii to come, so stay tuned to the site for further updates!