superann

This plugin filters the sitewide comments feed as well as individual post comment feeds.
Upon first-time installation and activation, all trackbacks will be removed from the default WordPress comments feeds. 
You can override this behavior on the options page and also use the comments or trackbacks only feeds described below.
URL for comments only feeds: add the variable “comments” to your feed query string.
<ul>
<li>http://mysite.com/comments/feed/?comments</li>
<li>http://mysite.com/?feed=rss2&withcomments=1&comments</li>
</ul>
URL for trackbacks only feeds: add the variable “trackbacks” to your feed query string.
<ul>
<li>http://mysite.com/comments/feed/?trackbacks</li>
<li>http://mysite.com/?feed=rss2&withcomments=1&trackbacks</li>
</ul>

Separate Feed Comments and Trackbacks

Remove trackbacks from your sitewide and individual post comment feeds, and/or have alternate feeds for comments or trackbacks only.

Nick Momrik

Automatically puts all trackbacks into the comment moderation queue.

Moderate Trackbacks

Automatically puts all trackbacks into the comment moderation queue.

Separate Feed Comments and Trackbacks vs Moderate Trackbacks