As you've probably already worked out, the Treyarch developed sequel is set in the future - 2025 to be exact - far enough to bring newfangled equipment into play, but not too distant to weigh you down with 'pew pew' laser handguns, plasma rifles and death rays. From a warfare point of view we're talking drones, primarily. No longer will humans be your only enemy: plodding and rolling assault drones with rifles/chainguns/rocket launchers strapped onto their sides are common foes, as are aerial mechs in the form of weaponised quadrotors.
While the majority of Black Ops 2's action is set to take place in 2025, you'll occasionally be leaping back to the land of Predator, Commando, and A-Ha in the mid-80s. The only 80's environment revealed so far is Afghanistan - a dusty set-up with horseback gunplay promised as your Black Ops team secretly meets up with Chinese forces to supply the Mujahedeen with weapons intended to fight the Soviet forces.
Interestingly, Black Ops 2 will also dispense with Call of Duty's linear storytelling and to introduce the element of choice.
At key points during the game you'll be presented with multiple options, and the path you choose will dictate the fate of those around you as well as your own. These choices are skill based: if you fail to protect a friendly, for example, their death or capture will trigger a splinter storyline rather than a fail state.
Treyarch's also confirmed 'Strike Force' RTS-come-sandbox style missions within the campaign that sees special Black Ops squads travelling the globe. Zombies are back and bigger than ever too.