http://gimmegimmegames.com/2012/09/dont-trade-in-your-wii-yet-nintendo-confirms-that-youll-need-both-your-old-wii-and-wii-u-to-transfer-datagames-between-systems/

Thank you for writing. 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. Transferred Wii content is accessible and can be played through Wii Mode, an application on the Wii U’s main menu. For updated information please keep checking our website at:

www.nintendo.com/wiiu

Sincerely,

Brian McFarlane
Nintendo of America Inc.

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http://www.nintendoworldreport.com/news/31715

The Wii U is to Wii as Wii was to GameCube.

Wii, WiiWare, and Virtual Console games will be supported on Wii U much the same way that GameCube titles were supported on Wii, without any special features or GamePad support.

In an interview with Nintendo of America, they stated that the Virtual Console transfer process was not confirmed to be available at launch, and would require both systems to be present and an SD card. The transfer process works much in the same way the DSi to 3DS process works today.

Good because I spent a lot on VC and WiiWare.

Good cuz I don't wanna have to plug in my Wii every time I feel like playing my VC titles.

cool this will shut people up before they start complaining!

Only a given though...  What was Nintendo going to do?  Say all your WW and VC purchases are void now?  Nintendo wouldn't dare do that or they would have to respond to me.

Its Nintendo. There will always be people complaining.

will we be able to transfer save data too?

I don't think the DSi - 3DS transfer supported that so my guess would probably be no. 

They confirmed some sort of transfer a while ago, this is just clarifying the details.

I'm still wondering if there's going to be some sort of filtering in place for save data, to try to weed out cheats/mods and such

well the 3ds and ds save their data on the game cards not the system. If data can't be transfered my wii will just stay plugged in when I eventually buy a wiiu.

Edit: replied to the wrong post, but anyway nintendo has always been supportive of keeping your old games and using them on a new system