Here's one of the recent trends I'm seeing in comment spam - content free comments that are vaguely flattering. Here's the text of one recent one I received:

Well said. I totally agree with you. The point you are making here does make sense. And all those who oppose your views actually lack the basic essence of the subject. You must keep doing the good work.

Is the goal here to lull someone into approving it because it is sort of positivish? This sets a bar for weblog participation - if your comment is generic enough to seem like spam, you probably shouldn't be leaving it. In that case, you "lack the basic essence of the subject."