I kinda don't understand the "I don't need a mic anyway" defense.
It's not like if you have a mic you're being forced out of your comfort zone of not talking to people. You can mute players in each game, turn your mic down, and/or can toggle your mic on & off.
It makes games about 700% more fun when you can get a hold of your buddies and be like "HOLY CRAP did you see that??? run dude! hey man, can you cover me for like two seconds while I make a break for Bravo? OH [dukar]!!!!! hahaha im dead" rather than, the Wii, for example, where you get to hear the TV quietly playing and maybe your fan in the background. You can't keep in contact with your friends in-game, you can't share hilariously awesome moments with each other, and it makes the gameplay extremely grating.... gets boring quick (unless you talk to your friend on a 360 if he has one). By the way: Wii Speak and its six compatible games don't count.
Personally, I don't talk in the games very much since I'm trying to concentrate. I usually have my mic on just in case someone says, "Hey Porsche, there's a dude comin' up on your right" or if we start talking about cars, other games, or whatever.
The Wii's communication is like sending a letter to a penpal in Japan.
The 360's communication is like talking to that same penpal instantly on Ventrilo/Skype/etc.