I intend to buy a Wii U (deluxe set) next month and am really looking forward to it, but as much as I would like to have my save data and Miis from my Wii on there, I am very disappointed to see that not only can you not decide what to transfer, but the transfer tool only works one-way (moves everything to Wii U and erases what is on the Wii). Ideally, I would rather have the option to copy all of the Wii's data onto the Wii U (and maybe have the ability to sync between the two with an SD card), as both consoles are in separate rooms and I'd like to have the ability to play on one console if someone is using the other room or console.
At the very least, it would be nice to move select save data and Miis to the Wii U, but this is not the case. It doesn't make sense, either, so why is the process all-or-nothing? I'm not looking to get rid of or stop playing the Wii or anything, and there are some games I'd rather play on the bigger TV than the smaller one, too (no upscaling, yes, but still…).