I haven't heard too much on the site and I know that as of right now, it only works with Animal Crossing but I'm curious how is it. Does it work well and reliably? I also have read that it sits on top of the Wii Sensor bar. Does it have to sit on top of it? I'm just looking for some info, thoughts and opinions on it.

Not sure how it works yet, but no, it doesn't have to sit on the sensor bar.

Was just reading about it on IGN. They described it as 'kinda-okay-sorta'.   It's as clear as a 360 headset at any right.  Too early to say about realibility but Nintendo's stuff is always reliable.

It doesn't need to sit on top of the sensor bar but it is intended to catch the voices of everyone in the room so it should be centrally located.

It doesn't have to be placed on top of the sensor bar.  If you keep your sensor bar below the TV, the instructions suggest that you place Wii Speak on top of the TV.

Wish they would hurry up and launch the Wii Speak channel already so I can try it out myself.

Well, here's my entertainment center setup.

I have the Sensor Bar on top of the TV. The Wii is on a shelf below the TV (and yep, that's a Dreamcast on the other side) along with various electronics placed in the TV stand. So I'm not sure where I'd put the Wii Speak device. I guess I'd have to see it in person, the size and how I could place it somewhere.

^ My set-up is very similar to yours, so I'd put mine up on top of the sensor bar.

I'm pretty excited about Wii Speak. I hope it works well. Are there any plans on getting it to work with older games?