Can I transfer the data from my Wii to my new Wii U without erasing the Wii?

I wasn't able to find any way to transfer the data from my old Wii to the new Wii U without running the Wii U Transfer Tool. I tried copying all my Miis to a Wii Remote but the new Mii editor under the Wii System Menu on the new Wii U doesn't offer a way to transfer to/from Wii Remotes. As expected, the Wii U Transfer Tool deleted all data off the old Wii.

However, I found a kludgy workaround: Before using the Wii U Transfer Tool, I had copied all my Miis to a Wii Remote, and I copied all my save game data to a different SD card first. It was a major pain, but it did allow me to keep a backup copy and restore the Miis to the old Wii after using the Wii U Transfer Tool.

I know this is late, but if you soft-modded your wii and have the Homebrew Channel installed, you can backup all of your Miis/Saves using this wii channel, http://wiibrew.org/wiki/SaveGame_Manager_GX Works great!