Currently, when viewing your feed or a tag, hovering over the comment icon will show you which user has most recently commented, but nowhere will hubski indicate the age of the post. Consequently, I'll often find an interesting submission that I wish to comment on, only to view the comments and discover the post has been dead for a month and is no longer worth typing up a comment for. Being able to see when the latest comment was would help me identify which comments are worth reading and which posts are worth commetning on at a glance.
Here's a quick mockup of what I mean:
It seems like a little thing, but it would actually improve my experience a ton.
Thanks for everything you guys do!