I’ve seen it on a few blogs and I must say I liked it a lot.
I just installed the CommentLuv plugin that basically checks the URL of a commenter and tries to recover a link to the latest blog post of that commenter to add it at the end of a comment.
I think this a great way to showcase the content of other blogger’s posts… and it gives the commenter the option to not link if they don’t wish to advertise.
(Maybe like people who don’t update their blogs all that often…. )
I hope you like it.