According to Kotaku, Nintendo confirmed to it that the Wii U Virtual Console won’t accept save data transfers from games bought through the original Wii’s Virtual Console.
The Wii U Virtual Console will function totally separate from the Wii’s VC, though you can access the original VC through the Wii Menu. The Wii U VC will also allow you to play Nintendo and Super Nintendo games on the GamePad and through the Wii U menu.
If you want to transfer games from the Wii to the Wii U, you have two options:
First, you can simply transfer your data to the Wii U and play your VC games through the original Wii Menu, including your saved data.
Second, transfer the data to the Wii U and pay a fee ($1 for NES, $1.50 for SNES) to re-buy the games through the Wii U’s VC. This option allows you to play the games on the GamePad, but doesn’t transfer your save data.