I really hope no one goes near this until there's a proper release. It's almost a guaranteed brick if you don't understand what you're doing.
I think people should at least go out and buy a DS game for Wii U. There is no harm in doing this other than that it costs money to do so.
At worst: If nothing happens with this, then you have a DS game you will either play or not play and are out some money.
At best: You may have a way to have a Priiloader like setup that protects against System Menu bricks or a direct boot the homebrew channel or RedNAND setup later on.
----------------------------- If you do not get a game
At best: You can buy a game later if something comes out and join in on the fun.
At worst: Nintendo releases a System Update then you need to hope that spoofing works to buy and download a game from the eShop on 5.5.1, The DS games are pulled from the eShop, or the DS emulator is silently updated one-by-one on the eShop so new downloads of any DS games are patched to prevent the exploit from working.