[ ] - Highlight all threads from this forum in What's New?
The result would look something like this:
You could use this for your important forums, such as announcements or site news, and have the unread important threads floated to the top - as per the attachment.
With border and/or background styling to visually highlight them, this will make such threads more visible to our members who regularly use XF by clicking "What's New?" and rarely visit the forums home page.