The Wii Speak Channel is out in Europe today, as is the actual WiiSpeak microphone. A helpful early adopter named Butulino has taken video footage of the "Canale Wii Speak" in action, so the rest of us can see what we have to look forward to
This video shows the channel's voice message capability, through which short (10 seconds or less) clips can be recorded and sent to Wii friends' Message Boards. Cleverly, the Channel allows you to bundle a picture with a message, so you can take a picture of that stringfish you caught in Animal Crossing and send it with a taunting message about, you know, how your friend has yet to catch a stringfish.
The Channel also allows users to warp their voices, in a feature similar to one found in the DSi's sound functionality -- which further cements the connection between the DSi's features and UI design and the Wii Menu.
[Update: it's up in North America! Nintendo almost succeeded in completely suppressing news of an available service, but not quite!]