Although it does cause some hiveminding, I like that the votes are visible to everyone. Many times I'm just skimming past comments, and if I see a +20 I know the person probably said something important, whereas otherwise I might have skipped over it.
Though, as a general rule, we probably shouldn't upvote comments found in this way.
Edit: and this comment is a perfect example of why we shouldn't. Ironically.
I'd like to see, beside the cumulative karma as it is now, also its analytic. Does my 0 points somewhere means no upvotes and no downvotes or +7 and -7, for example?
A timeline graph would also be appreciated.