Starting in AIR 2, you can capture raw microphone data as a byte array of floating point values representing monophonic audio data. See http://help.adobe.com/en_US/as3/dev/WS5b3ccc516d4fbf351e63e3d118a9b90204-7d1d.html.
As for video, you can currently only capture it to play back locally, using both the flash.media.Camera and flash.media.Video classes. You can upload it to Flash Media Server using the flash.net.NetConnection class. See http://help.adobe.com/en_US/as3/dev/WS5b3ccc516d4fbf351e63e3d118a9b90204-7d50.html.
Hope that helps,
Thanks, Frank! This is very helpful.