You're correct, John deliberately changed this as he thought it was a bug. I'll chat to some people to work out what the desired behaviour is.
Previous behavior was chosen intentionally, see this thread for the discussion. I think the change should be reverted.
It seems that if you look at the column on the right of the page, you can see upvotes and downvotes separately for recent posts. The same [n, m] format is displayed for recent comments, but it doesn't seem to actually sync with the score displaying on the comment. This feature only seems available on the sidebar: looking at the actual comment or post doesn't give you this information.
Thanks, whoever did this!