Much cleaner and more appealing design
Ability to block users
Ability to mark users as favorites to easily track their posts
Ability to mark topics as favorites for easy access
Ability to customize the order of the forums
Ability to minimize forums you don't care about
Ability to rate posts. Posts or topics below your custom rating level will be minimized.
Owners of private forums will be able to set access themselves
Much better text and table posting -- IE and FF will both work the same and work well.
Ability to easily post links to boxscores, player profiles, etc., across all games
New forum rating and new user rating system
Much, much more