Performance improvement.
All maps from previous and future CoDs added as default.
Radiant for everyone (not dev only).
Zombies brought to multiplayer, but no stupid stuff like 64 player Zombies, the stock Zombies, leave the stupid stuff to modders.
Zombies should be in the same dedicated server browser as multiplayer and be counted as a gamemode so you can filter through for zombie games.
Friends system that is based off the forums.
Mods filter that actually works (doesn't really work on 4D1/IW4M).
Some DVARs unlocked.