I know some of this has already been here. But, here is a full article on all announcements. To me, this is bigger than SSBB. Bolded the big stuff.

Source

"With Smash Bros. at last out (in Japan, at least), Nintendo appears to have penciled in Mario Kart as its next big title. We're assuming that much, considering the unexpected blowout on the game in the latest issue of Famitsu.

The Wii installment of the cart racer that started it all looks like it's going to have lots of variety. Famitsu reveals a total of 32 courses, with 16 remakes of old courses, and 16 completely new courses. New courses include Mario Circuit, Momo Country, Kinopio Factory, DK Snowboard Cross, Coconuts Mall, Kinoko Canyon, and Luigi Circuit.

Some of these courses will put a new feature of the karts to use: mid-air tricks! Karts and bikes are both capable of performing actions and tricks in the air. Get a trick just right, and your cart will perform a dash upon landing.

In addition to a ton of content, Mario Kart Wii will have some serious multiplayer options. The game will include Wi-Fi based play for up to 12 players. You'll be able to select to play against players from throughout the world, players in your country, and players on your friend list.

As part of the new network mode, Nintendo will be making use of the Wii's Channel interface in yet another unique way. We're not sure of the specifics, but it seems that you'll be able to install a Mario Kart Channel to your Wii hub to view world rankings as well as your own records.

Going along with the Wi-Fi multiplayer play, Nintendo will be giving players a means of customizing the game. You'll be able to make your very own Mii ride a bike or kart, adding that bit of you to online races.

The online mode will also expand the single player fun. The game will offer downloadable ghost data, so you can play against some of the best players.

Not big on the whole internet thing? In addition to the Wi-Fi play, the game will also let players play together the old fashioned way: through split screen for up to four.

With this Famitsu blowout just hitting Japan, we expect the Nintendo marketing machine to start getting into gear and remind everyone why Mario Kart is so great. If, as a part of that initiative, we get a chance to sample the Wii installment in advance, you can be sure we'll let you know."

DK Snowboard Cross?

hmm, there's online leader board for Mario Kart? But not for SSBB????

Question: 4 player split screen + WiFi...possible? Because I can't see it being fun any other way...

kingofwale, there's a leaderboard for Mario Strikers Charged too.

PS:  It sucks!  Too many people with no lives, cheaters, I don't know...all a leaderboard does is tell you that you don't play as much as a 10 year old, therefore you remain on the middle of the list forever.

leader board =]
+100million sales

>kingofwale, there's a leaderboard for Mario Strikers Charged too.

I know that, I am merely question why there isn't one for SSBB.

Doesn't the leaderboard just track best times? Or does it count wins/losses and stuff? I'm cool with keeping track of best times (like Mario and Sonic does) but I don't want a win/loss record...

Anyways I can't wait to play this game, it sounds great! SSBB and MKWii coming out in the same year...am I dreaming?

The leaderboard thing is sweet...so is the ghost data....ok the whole damn thing is sweet.

I'll admit my past transgressions and say that I've never personally owned a Mario Kart game...but I will be rectifying that problem this time around. This sounds like a lot of fun =)

 Why do you question that?