A thought on trackbacks
To wit: if you feel that comments are a conversation, trackbacks are an annoying distraction; they are an attempt to pull people away from the conversation to another site (or page). However, if comments are a collection of reactions, trackbacks are clearly desirable; they aggregate the reactions on other sites into one place.
My personal view is that I am most interested in comments as a conversation, and so I don't find plain trackbacks very useful as they're usually done. They could be useful if the blog author exercised some sort of editorial oversight on what trackbacks showed up, putting up only the ones that they felt added something interesting to the overall reactions, but I suspect that exercising this level of selection would make at least some blog authors uncomfortable; it'd feel sort of like moderating your comments and only letting through the 'useful' ones.
(My attitude on trackbacks is ambivalent; I like the information for my own use, but I'm not sure I'd display trackback results on WanderingThoughts even if I had the feature implemented.)