Nintendo in the UK has announced that - like its North American counterpart - it too will fix Wiis that ceased to work properly following the 4.2 system update, for free. It's stating that the number of reported issues has been small.
That said, it is also taking responsibility to fix those machines that have suffered. In a statement to the press it says:
"If anyone is experiencing problems with their Wii console after downloading Wii System Menu 4.2, and believe their system has not been modified, please contact our customer service centre. If we find that you have a normal system and the update has caused your system to not work, we will repair it at no charge.
"Please do not return anything to our customer service department without contacting them first for advice." The problem occurs during installation of firmware version 4.2, which reportedly crashes part-way through and therefore upsets the digital innards of the machine. "