i'm no xsl pro, but understand the basics enough to add to this. 

i basically modified the sample you posted and got it to be able to embed the youtube clips into the page.  i verified this works.  i took out the more free-form item/description elements since people may or may not want those in.  i verified this works on a testing dnn 4.5.5 install. 

here's the modified version:

<?xml version="1.0"?>
<xsl:stylesheet version="1.0"
xmlns:media="http://search.yahoo.com/mrss/"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<!-- xmlns:xsl="http://www.w3.org/TR/WD-xsl" -->
<!-- RSSv2YouTube XSL by Phil 'iwonder' Guerra -->

<xsl:output method="html" indent="yes"/>
<xsl:param name="TITLE"/>
<xsl:template match="rss">

 <xsl:apply-templates select="channel" />

 <xsl:apply-templates select="channel/item" />

</xsl:template>

 <xsl:template match="channel">
  <strong><a href="{link}" target="_blank"><xsl:value-of select="title"/></a></strong><br/>

<!--  <font size="-3"> -->
<!--  <xsl:value-of select="description" disable-output-escaping="yes"/> -->
<!--  <strong>Language: </strong><xsl:value-of select="language"/><br/> -->
<!--  (<xsl:value-of select="copyright"/>) -->
<!--  <strong>WebMaster: </strong><xsl:value-of select="webMaster"/> -->
<!--  </font>-->

  <hr/>
 </xsl:template>

<xsl:template match="channel/item">

 <strong><a href="{link}" target="_blank">
  <xsl:value-of select="title"/>
 </a></strong>
 <br/>

 <font size="-3">(<xsl:value-of select="pubDate"/>)</font>
 <br/>
  
<!--   <xsl:value-of select="description" disable-output-escaping="yes"/>
   <br/>-->
  
 <xsl:if test="enclosure/@type='application/x-shockwave-flash'">
  <object width="{media:thumbnail/@width}" height="{media:thumbnail/@height}"><param name="movie" value="{enclosure/@url}"></param><param name="wmode" value="transparent"></param><embed src="{enclosure/@url}" type="application/x-shockwave-flash" wmode="transparent" width="{media:thumbnail/@width}" height="{media:thumbnail/@height}"></embed></object>
  <br/>
  <a href="{link}" target="_blank">open in browser</a>
  <br/>
 </xsl:if>

 <hr/>
</xsl:template>

</xsl:stylesheet>

Ok, just wanted to show a slight variation.  The tags that specify media width, and height, look nice for a thumbnail size, but for us older folks - the embedded video control needs to be a bit bigger, otherwise, I'd just view it on YouTube.  Also, included an example of how to go about taking apart elements of a tag to get the info you want.  The item description contains a bit more info than I wanted, so I stripped out just the main descriptions sans the image, and other keywords stuff.

Another option for displaying this type of feed with a bit more control over what elements you want to display without hardcoding in the xsl, is to use the XML/XSL module.  With that module, you could create parameters to pass an xsl that could be used to test whether to show a specifc tag or not.  I'll post something over on that forum when I get around to it.  But for now, this is the xsl I'm using.  Feel free to use it, and tweak as needed.

Now, when can we expect the Core Team blogging on YouTube, and showing this type of newsfeed on the DNN site?  Would make a nice addition for the upcoming OpenSource gathering in Europe for those not being able to attend.  A nice travel log.  What say you?

<?xml version="1.0"?>
<xsl:stylesheet version="1.0"
xmlns:media="http://search.yahoo.com/mrss/"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<!-- xmlns:xsl="http://www.w3.org/TR/WD-xsl" -->
<!-- RSSv2YouTube XSL -->
<!--   by Phil 'iwonder' Guerra -->
<xsl:output method="html" indent="yes"/>
<xsl:param name="TITLE"/>
<xsl:template match="rss">
<xsl:apply-templates select="channel" />
 <xsl:apply-templates select="channel/item" />
</xsl:template>
<xsl:template match="channel">
  <strong><a href="{link}" target="_blank"><xsl:value-of select="title"/></a></strong><br/>
  <font size="-3">
  <xsl:value-of select="substring-after(description,'/>')" disable-output-escaping="yes"/></font>
  <hr/>
</xsl:template>
<xsl:template match="channel/item">
<xsl:variable name="FirstPartDesc" select="substring-after(description,'/>')"/>
<xsl:variable name="JustText" select="substring-before($FirstPartDesc,'Author')"/>
<table>
 <tr>
  <td valign="top" width="50%"><font size="-2">
 <strong><a href="{link}" target="_blank">
 <xsl:value-of select="title"/>
  </a></strong>
  <br/>
  <font size="-1">Author: <xsl:value-of select="author"/></font> <br/>
  <font size="-3">(Published: <xsl:value-of select="pubDate"/>)</font><br/>
<xsl:value-of select="$JustText" disable-output-escaping="yes"/></font></td>
 <xsl:if test="enclosure/@type='application/x-shockwave-flash'">
  <td valign="top" width="50%" align="center"><font size="-3"><center>Click Image To Use the Control</center></font>
<br/>
  <object align="right" width="280" height="210">
  <param name="movie" value="{enclosure/@url}"></param>
  <param name="wmode" value="transparent"></param>
    <embed src="{enclosure/@url}" type="application/x-shockwave-flash" wmode="transparent" width="280" height="210"></embed>
 </object>
<br/>
  <a href="{link}" target="_blank"><font size="-3"><center>Click Here to See it at YouTube</center></font></a>
</td>
 </xsl:if>
</tr></table>
 <hr/>
</xsl:template>
</xsl:stylesheet>