- Wider post area
- Up to down post order
- Add/remove text formatting (no colors)
- Add image (upload only)
- Mention people and groups
- Anchored links
- Page numbering
- BBcode
However do notice that if you had links to the older forum format in Discussions, they will take you to the old forum format. You would have to pick and update the new links to redirect people to the new format.
Here's a few links for a comparison:
Community updates in old format
New community center announcement