Link: http://www.vooks.net/story-18483-Wii-Menu-System-Menu-42-released--homebrewers-be-warned.html
The Wii Firmware has been updated to version 4.2, and it seems to be required in order to access the Shop channel.
Homebrewers (both legal [community developed games] and illegal [online cheating, pirating]) be warned that this does stop homebrew from working for the moment.
Thats all that has been reported. I can't find any info about anything else it does, other than stopping homebrew. I will update in a moment, and report back with any changes I notice. But so far it looks like it doesn't actually do anything except stop homebrew. Perhaps it updates the Nintendo Channel for Europe/Australia? Who knows!
EDIT: Please do not turn this topic into a discussion on how to install homebrew or how to pirate games. I don't want it to get deleted.

