They did implement something like this a few months ago. Rising new comments are randomly shown on the frontpage. Try refreshing the frontpage a few times and y

They did implement something like this a few months ago. Rising new comments are randomly shown on the frontpage. Try refreshing the frontpage a few times and you'll see various submissions with ~5 upvotes appearing and disappearing at random. I agree it could be better though, and I like the idea of putting them in a highlighted section rather than randomly sprinkling them in the middle of the page where they don't stand out.