We reported earlier that trading in your Wii to Gamestop will land you $50 credit towards the purchase of a new Wii U. However, you will need to keep your Wii if you want to transfer save files, Wii Ware, and Virtual Console games.
Gimmie Gimmie Games asked Nintendo and reported as such:
I can confirm that you will be able to transfer your content from your Wii to the new Wii U. Wii U owners can wirelessly transfer content such as Miis, and WiiWare and Virtual Console games to their Wii U systems. Both systems will need to be connected to the Internet and the Wii U will need an SD card to facilitate the transfer. The process is very similar to transferring content from Nintendo DS to Nintendo 3DS or from Nintendo 3DS to Nintendo 3DS XL; which has been received positively by consumers.
So, your Wii will hold one last final purpose before it goes into the depths of your closet forever. How much are your save data, entry logs, Virtual Console, and Wii Ware games worth to you? Looks like some gamers have some prioritizing to do, but that’s certainly a lot to give up for $50.