Nintendo of America's Bill Trinen states that 3DS Miis are "too complex" for Wii.
http://www.nintendoworldreport.com/news/24803
In an interview with Joystiq.com, Nintendo of America's Bill Trinen noted that you will be able to import a Mii from the Wii to the 3DS, but it will be impossible to export a Mii from the 3DS to Wii.
The Product Marketing Manager for NOA called the process a "one way transfer." He noted that the 3DS' Mii Maker has additional facial features (such as eyes and hairstyles) that are not present in Wii's Mii Channel.
As previously noted, the 3DS will be able to create Miis automatically. Using the dual cameras on the back of the unit, the 3DS' Mii Maker will take a 3D picture and convert it into a Mii.
stupid question:
So that mii i had on my wii since launch I send to my 3DS I'll lose it forever? Or will it just copy it over. One way transfer is scary idea
Will they be exportable to the Wii 2?
However, if anyone wants me to leave this forum I will do so and never return.