Some North American and UK consoles are getting bricked.
Nintendo of America released Wii system update 4.2 on Tuesday, a patch that reportedly had the intention of shutting down Wii hacking solutions. The popular Wii Homebrew Channel is removed by the update, and several known exploits (both hardware and software) are eliminated along with the ability to use USB loaders or downgrade your Wii firmware. The Wii Shop Channel was also updated to reflect the new firmware.
Unfortunately, the update has apparently had an unintended side effect: some Wii consoles are getting bricked by the patch, despite the fact that they are unmodified and have not been tampered with in any way. A post by "NOA_TECH_JANE" on the Nintendo of America Tech Support forums confirms as much, extending an offer to repair affected consoles free of charge. Nintendo's UK branch also confirmed to Edge that a small subset of UK gamers are also experiencing the issue.
Any North American Wii owners experiencing this issue can contact Nintendo of America's Tech Support line at 1-800-255-3700, 7 days a week between the hours of 6am and 7pm Pacific time.