This is the code I'm trying to embed:
<object width="480" height="385"><param name="movie" value="http://www.youtube.com/v/jJECepNeCJ0&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/jJECepNeCJ0&hl=en_US&fs=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="480" height="385"></embed></object>
The interesting thing is that this code seems to display the embedded video in the Preview immediately below the form. Once the form is saved, the code snippet is rendered as text.