With the campaign time setting being 13 years in the future. The technology/weaponry and how the general warfare is carried out can become a lot more “flexible”. Whether or not this pushes Black Ops 2 too far over the edge into some sci-fi FPS instead of having the feel of the rest of the Call Of Duty series I'm not quite sure. But we will soon find out. Also its confirmed to be a direct lead on to the Black Ops 1 Storyline.
Now I've never been one to sit down and play the single player campaign, I'm more competitive multiplayer man. And when it comes to that it sounds as though Treyarch has done it extremely well. All of the weapons I've seen seem balanced compared to one another (eg. You can shoot people through solid walls with a sniper however it requires you to charge a shot first) Also with countdown timers in LAN games and and whole lot of other small features competitive play looks like its going to get alot more interesting. With Elite 2.0 coming out and also rumors of possible BO2 MLG tournaments, the future is hopeful.
BRAINS!!! Whoops I mean zombies… Hordes and hordes of zombies. Treyarch has succesfully made us hunger for more and it looks as if Black Ops 2 is going to do more than quench that thirst. With an optimised zombies, it means up to 8 player zombies and alot more zombies. Treyach hasnt stopped there though. They have a full sized team developing the Zombies part of the game and its FULLY integrated into the multiplayer engine. With unique gamemodes such as 4 v 4 score based zombies to be one. There will always be more ways to play. Also the maps seem alot more open so it wont be as easy to get stuck on a chair or in a doorway. On the topic of maps the smallest zombies map on BO2 is said to be larger that EVERY BO1 zombies map. So it sounds awesome.
All in all I would say its going to have its ups and downs like every CoD game. But as always there's plenty of ways to play and the game will be very re-playable. I can guarantee I will get this game and you should too.