For those of you who didn't know, Treyarch and Activision has been uploading videos from Theater Mode to Youtube. Not sure if they are doing PC, but they are doing PS3 and Xbox360. Here are the links...
Xbox360 - YouTube - CODblackopsXBOX's Channel
PS3 - YouTube - CODblackopsPS's Channel
In order to get your video on the Youtube channel you must first cut a clip of a video from your Recent Games. After you've cut a clip, save it and then go to your file share and chose the clip. Then click Render and it will begin to upload your video to the youtube channel of the system you play. The youtube channel loads Suuuuuper Sloooooow cause there are so many videos so I suggest going to the search feature on Youtube and type in your Gamertag or PSN ID and then hit recently uploaded in the advanced search. You can download your video and upload it to your youtube channel by using Keep Vid KeepVid: Download and save any video from Youtube, Dailymotion, Metacafe, iFilm and more! The video is NOT in HD just so you know, so the quality could be pretty bad. I hope you enjoy and remember the video will only show up on the Youtube channel if you render it.