Awesome list on new and confirmed things:
https://www.reddit.com/r/battlefield_4/comments/1g7qls/bf4_running_list_of_things_weve_learned_so_far/For example:
VoIP for PC
Battlepacks:
Through the course of their multiplayer career, players will receive Battlepacks containing random combinations of new camos, dog tags, knives, XP boosts, and gun attachments. These items are designed to add customization options while not being game-changing. *Credit to u/AdiAir
Motion sensor balls for Recon
C4 for Recon class
C4 can now be thrown (at a limited distance)
Customizable secondary weapons (i.e barrels for pistols, sights and camos)
Suppressing a Recon only possible by Support class (making players screen blur)
5 person squads
2 types of med packs. A smaller one which can be tossed to trapped teammate or stuck onto a passerby
Levolution of buildings is not scripted, requires team effort
64 players on all platforms (66 players counting Commanders for both teams
Spectator Mode (Confirmed for "nextgen" consoles) submitted by u/phresch
Flash bangs
Incendiary grenades
Weapons (pistols) can now be fired while swimming
Kill assists of 90+ now count as kills. Possibly counting as kills for both players, also possibly on kills assists above 50
Angled grips for primary weapons
Ability to click on a base on the map to spawn there
3 team factions, USA, Russia and China
You can shoot fire extinguishers to get a smokescreen
sprint swimming and ability to dive underwater for stealth
Dynamic environment, area will remain dusty/cloudy after heavy damage or demolition of a building
Addition of side sights (side mounted iron sights) to primary guns for closed quarters combat (will not distort FOV)
Addition of working elevators.
Addition of deploy-able road blocks for stopping road traffic.
Perk bar reset on squad wipe
and many more things....