I have seen a rash of trackback spams that have the regular nasty messages in them but they have put regular valid domains in the trackback and comment spam. Here are the three that I see showing up today.
google.com, msn.con, blogspot.com, sixapart.com, movabletype.com, technorati.com, feedburner.com and pubsub.com
It is obvious that the trackback and comment spammers are not happy that their traffic is being neutralized which is disturbing because it could be a sign of a all out war that is about to be begun.