Nintendo will be killing off the Wii Speak add-on that is used for voice chat on the Wii console. Starting today, the Wii Speak will only be available at retailers in limited numbers. Sources tell us that unless Nintendo sees a significant increase in demand for Wii Speak, it will discontinue the add-on altogether.

It is hard to tell what might have triggered this decision beyond poor sales. The Wii Speak microphone allows users to chat via the Wii Speak Channel for which it is designed. It does not allow in-game chat, but does allow chat between your Mii avatars and your friend’s Mii avatars using the Wii Speak Channel. Nintendo had nothing to say about the future of the Wii Speak Channel.

According to several sources that we spoke with, the lack of support beyond the Wii Speak Channel is what they believe is hurting sales of the device. It just does not offer much beyond the Wii Speak Channel and that is the major reason for the slow sales.

Nintendo does point out that you can still get the Headbanger Headset from Performance Designed Products which owners can use for voice chat in games. Still, the use of the alphanumeric “friend code” system (rather than an open user name system found on other consoles) does seem to be contributing to the issues with voice chat on the Wii.

As with many analysts we continue to view the lack of a more open social structure as one of the major shortcomings of the Wii platform; and we believe it still contributes to the major reason that many Wii owners never bother to connect their console to the Internet. In the meantime, if you want a Wii Speak to add to your Wii collection we suggest that you might want to snap one up quickly.