now keep in mind, this isn't a Wii Update, it's just an update for the Nintendo Channel! You won't get prompted to update your wii, just that channel (if you even have it installed)
I was able to browse my Wii normally and even go into the Shop Channel with no problems but on the main page of the Shop Channel is a link to the updated "Nintendo Channel"
"An updated version of the Nintendo Channel is now available. This version includes improvements to the channel's functionality and can be found as a free download in the Wii Channels section of the Wii Shop Channel. If you're on of the many that have been using the channel and exploring its exciting content, you will be required to download the updated version before you can use the Nintendo Channel again. If you're downloading the channel for the first time, the updated version will automatically be downloaded."