http://wiinintendo.net/2008/05/11/more-mario-kart-wii-package-update-info/

I'm calling it fake, though I don't know the validity of the site.

Seems like something nintendo would never do.

Though it would be nice

edit by heysuburbia:

This appears to be fake, here is the link to the Iwata asks Mario Kart Wii page and there is nothing about the new levels on there.  You’ll also notice the wrong type-face and bad formatting in the screen shots.  Link:

http://us.wii.com/iwata_asks/mariokart/vol1_page1.jsp


I actually read that session of Iwata Asks a couple days ago in its entirety and it doesn't say anything about package updates. Also, even if they were going to do something like that, they wouldn't do it so soon.