I'm also very happy like another poster on this thread that MK will not be online. It would ruin the simplicity of just playing a game.
Do I want to share all of my experience with the world?
Would I have to to fully enjoy it?
A game being online does not make it better, nor does a game that has had multiplayer in the past need to be online today.
Mario Kart is simply race. It's a simple experience.
A true online game is a game like Pokemon were one would get their moneys worth off a subscription.
(Leveling up Pokemon to suprise online oponents with well thought out battle strategies and thousands of options for online players just from the pokemon and their abilities alone.)
And of course no other current system can link like this: GBA-->GC-->Online
Online and extras to keeps players busy would dilute the whole Mario Kart experience.
(I heard some folks in the past asking for custom Karts and such) I'm almost certain those folk are truly asking for a different racing title entirely.
Mario Kart online would not have the same impact as it would as a personal experience.
Thank goodness. Save it for another racing game a GT or Apex clone perhaps.
(also I read:
http://www.the-magicbox.com/game030203.htmthat the English translation is already done for MK. I just want to say "Thank you Nintendo!" Since I've complained about lateness in their releases in the past).