If you go to battlelog and look at your weapons list, it now shows the China Rising DLC weapons. These weapons will be unlocked by completing single game assignments (something like get one kill with a grenade, one kill with a sniper, one kill with a defibrillator, and one kill with an assault rifle, all in the same game).
L85A2 : Assault
MTAR-21 : Carbine
RPK-74M : LMG
MP7 : PDW
L96A1 : Sniper
Also, there are some new black-background dog tags.
I think the release date for the China Rising DLC is Dec 3 for Premium members (available two weeks later for everyone to purchase). Oddly enough, the Second Assault DLC should be available for Xbox One players upon release (not sure about premium vs not premium), but I don't see those weapons listed on Battlelog. Perhaps because it still sees me as an Xbox 360 player.
The Second Assault weapons are the F2000, AS Val, M60E4, DAO-12, GOL Magnum (all were in BF3 except for the GOL Magnum sniper rifle). I'm not sure if there will be assignments to unlock these.