Per Max501 request I've added new custom BBC codes for embedding Youtube, Vimeo and Google video clips into the posts. In order to do so you need to be able to find out and use a proper video clip ID.
The new BBC codes are:
[youtube]<your_youtube_clip_id>[/youtube]
[vimeo]<your_vimeo_clip_id>[/vimeo]
[googlevid]<your_google_video_clip_id>[/googlevid]
For example looking at Youtube clip link http://www.youtube.com/watch?v=gvFiUfAKcf8
the video clip ID shows directly in this URI as gvFiUfAKcf8 (the letters/digits combination following the equal sign). The same clip ID value also shows in the "URL" and "Embed" windows of the Youtube page.
There are two new buttons on the post editor page showing the new "youtube" and "vimeo" BBC codes options. I did not add "googlevid" button since it is not used here so far but if you'll need to embed Google clips you can do it by typing the [googlevid]<your_google_video_clip_id>[/googlevid] directly into your post text.
So in order to embed the youtube video clip push the "youtube" button and type or copy & paste the clip ID from the link between the BBC tags. No extra space characters allowed !!!
For the link shown above the proper text in your post shall look like:
[youtube]gvFiUfAKcf8[/youtube]
The examples of the embedded clips are in the follow-up post.