Scott Johnson of Feedster: "Clearly this could be easily done through an RSS 2.0 namespace extension [cut] So its not a question of "can it be done" but more "should it be done".
Randy: IMHO, trackbacks as commented-out RDF w/in your HTML is nothing more than a lazy programmer's hack, but trackbacks in your RSS is a well architected solution. Check out my RSS feed. The trackbacks have been in place for some time.
SEO's generally don't have a grasp of the technology to do an automated post, automated comment or automated trackback. Most blog SPAM comes from manual entry by a persistant SEO. Now, don't get me wrong, trackback SPAM is on the uptake and they'll eventually figure out how to do the automated trackback via RSS, so be prepared w/ a neat little feature to either approve comments individually or delete them individually.
Update: Here's the link to the Trackbacks in RSS specification.
