Topic: Can I save game data to SD card and use on another Wii U?

We just got Super Mario 3D Worlds. I want to know if we can save our game data to an SD card, take the SD card and our game disc to another Wii U and continue playing from where we left off? Can this work for other games too or are we bound to playing from saved data on our Wii U only?

No. The Wii U does not use the SD slot except for Wii games

Your save data is stored on the system, so it can't be transferred or copied to another system.

So there is no way to move your game data with you so as long as you have your game disc and another Wii U simply as a game host you can continue where you left off?

Unfortunately, at the moment, that's not possible. Of course, there's nothing stopping you from creating a file on the other Wii U using the same game disc, but I'm afraid you can't take your save data with you. That has to stay on the system it was created on.

There maybe a way, but I can't say for definite if it'll work.
What you could do is use an old mp3 player if you have one. Plug it into the wiiu and format it in the memory section (don't forget to back up any files saved on the mp3 first). Once it's been formatted, copy your saves onto your mp3. Use copy, not move, because you don't want to lose your original save files.
Plug your mp3 into the target WiiU and go to the memory section to see if you can copy over your game saves.