Wii Freeloader is firmware-proof, says Datel
According to this, the Wii version of Freeloader can't be beaten by firmware uprages. The device allows any Wii to play import games, so you can buy a game from the US or Japan and play it in your European Wii.
"We can confirm that on every occasion that the product is used when the disc is inserted in the console that it allows the usage of any imported Wii game discs and disables the console from been able to update its firmware, if the disc is removed after been inserted and reinserted this will again enable the console to update its firmware but still allow the usage of the any imported Wii game discs," said manufacturer Datel.
Freeloader for Wii should release in the middle of March.