Gameplay:
-more realistic dying animation
-more realistic dying sounds
-detailed statistics of the player's profile (multiplayer and singleplayer)
-cover mode (if pressed player uses wall or obstacle and takes cover behind it)
-tutorial explaining the multiplayer
-AIs with skill lower than half should sometimes flee when outnumbered badly
Game engine:
-more focus on game engine performance
AI:
-AIs not stuck anymore trying to "get in" a vehicle
-better Path finding
-ai drivers have better solutions escaping after a crash with their vehicle
-AI takes cover by itself when possible
-AI tries to escape if ambushed from several angles
-AI doesn't overrun other AI accidently
-AI should react much quicker (melee?) when player stands directly in front of them