While the chip is there, there is no inherent microphone function in the Wii Remote. Even the article you link to says it’s not used yet. However, you never know what the future holds for new accessories that would attach much like the nunchuk! We’ve created a microphone accessory for the Nintendo 64, Nintendo GameCube, and built one into the Nintendo DS/DS Lite, so it goes to reason we might think ahead in case we ever want to build one for the Wii! Keep an eye on http://www.nintendo.com for official information.
Nintendo of America Inc.