The new forum allows for direct upload of screenshots without outside hosting. It also allows embedding of YouTube and Vimeo videos when starting a new topic. The forum also allows you to follow individuals which is important if the post about an area of interest. These are major improvements.
These are minor items that many have allowed for a long time. Heck, my own forums have allowed it for nearly 5 years. The problem is the layout which is much harder to follow than the previous version.