A lot of black ops 2 confirmed stuff has been shown at Gamescom, Black Ops 2 Full Multiplayer Gameplay shows to us the new black ops 2 weapons maps and perks.
Black Ops 2 perks will still as usual in the form of 3 tiers, and you can pick one from each tier.
Black Ops 2 Weapons will be completely different from those present in Black Ops and slight similar to MW3 weapons.
Black Ops 2 Maps are characterized by being bigger and the confirmed maps till now are Cargo, Aftermath, Yemen and Turbine.
There are two confirmed game modes, Hard point game-mode and Team death match which will contain 18 player only.
More info at black ops 2 full multiplayer gameplay