genkisan

<ul>
<li>grab youtube video comments and insert into your blog post</li>
<li>schedule hourly, daily, weekly</li>
<li>manual update</li>
</ul>
Demo: 
<a href="http://ericulous.com/2007/05/16/wp-plugin-genki-youtube-comments/" rel="nofollow ugc">Plugin Details & Demo</a>

Genki Youtube Comments

Grab YouTube video comments and insert into your blog post

sydcode

This plugin finds YouTube links in post content and imports the video comments. 
Users may also post comments to the video after signing into YouTube.

YouTube Comments

This plugin finds YouTube links in post content and imports the video comments.

Genki Youtube Comments vs YouTube Comments