I just have some suggestions:
- The "Last comment" metadata should instead show when the comment was posted relative to the current time. For "Last comment posted X minutes/hours/days ago". This is a lot more informative than a general date as it gives a good idea to the user how "old" the discussion is without requiring looking at a calendar or doing a bit of math.
- The "Last comment" metadata should be clickable and clicking it should scroll you to and highlight the latest comment.
- The number of people in the discussion label should be clickable and open a menu that lists everyone involved in the discussion and links to their userpage.