Previously requested: When you add categories to the muted categories in your user preferences, they won’t show on the latest page anymore.
The tracked categories automatic get added to your unread list, and the watched ones will show as if you were watching them, you get notified of new posts.
Also possible now: sorting the main list, rss. Starring posts (they’ll show in the starred list)
Long possible but perhaps not known: Replying to posts via email. When you’ve setup notifications for a category, you can reply to any mail talk sends you you.