WiiSpeak isn't the kind of thing we can imagine selling in Wii Fit quantities, but it's getting hard to tell nowadays. Maybe the microphone add-on and Animal Crossing: City Folk will be overshadowed by the other big first-party release of November, and supplies will be plentiful, but why take the risk? You can now preorder your own WiiSpeak at Amazon, and rest assured that you'll be able to bitch behind Nook's back with your Wii Friends from day one. Hang around now, and you may be confined to the keyboard.
[Update: Removed potentially confusing comment]