I think people said internal mics should work under boot camp.
Here is some info: "All you have to do is make sure it is selected in volume control. However, by default, volume control does not show the recording device options, so if you're new to windows you might not know how to select different recording sources. Go to volume control, options, properties, select the radio button marked recording, click ok, click the check box below the microphone section."
Source: http://forum.onmac.net/archive/index.php/t-1300.html