Turns out the mic on the kinect is surprisingly good.
Here's the thing. If you don't have background noise to worry about, you can use the kinect as your main chat mic.
My brother and I were both in a party with our headsets for audio. Chat was also coming through the headsets, but we were using the kinect for voice. Not using the pack in.
It doesn't sound as good as the included chat headset, but it sounds pretty good. I sit about 5 feet away from the kinect and it just worked. Of course it's better to use the pack in when you want the mic close to your face, but if other noise isn't an issue, it's convenient. Works better when you're using a headset for audio, but I imagine even people getting it through their TV might find a use for it.
Was not expecting that at all.