OK, testing.
I think it's like this. Under the video, there's a small box with the word 'Embed' inside. If you scroll over that, a little sign reading 'Get video embed code' comes up. Click on that box, and another box opens below it with some highlighted text (it should read 'object width="480...." ') Copy and paste that text, which is the embed code, into your post.
If I've done it right, it should work. Let's see:
<object width="480" height="385"><param name="movie" value="http://www.youtube.com/v/S3CJIKKSUpg&hl=en_US&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/S3CJIKKSUpg&hl=en_US&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="480" height="385"></embed></object>
Yep, that's how they're doing it now.