Just a few minutes ago, Nintendo released a brand new update which allows Wii users to load games directly from the SD card, but not only that, from SDHC cards as well! This firmware update is definitely the definitive storage solution Nintendo had talked about in the past. Joystiq confirms that the update is available in America, while I can personally confirm the update is also available in Europe. We assume, this update is available worldwide.
The storage solution still cannot unfortunately load save games from the SD card, however, this is likely due to the SDK not having this option in the first place.
There are three small differences to the SD Menu and the Wii Menu. The first, being the channel preview having a default “tune” and only showing the channel’s logo when selecting the channel from the menu. The second and third are simple aesthetic changes, namely, the background and bottom bar being black. I can also confirm that The Homebrew Channel works on the SD Card menu, which is great for all of our users running homebrew.
Update: The new Wii system update also adds support for SDHC cards up to 32 GB — that’s alotta Virtual Console games folks!