not much, except that BO2 zombies mode got even more better (bigger maps, more perks, new gamemode like grief, create weapons and shields and BUS!!) and multiplayer experience got revamped (?), only known is the livestream to YouTube, much futuristic weapons, new kill streak awards etc. Single player story is going to be the best, i think.

P/S: FYI, Treyarch got better post launch support to PC players (?) than Infinity Ward, since they only want cashcow console $$, sry if offended.
P/S 2: Since COD4, most ppl said that COD is going down due to Activision and Infinity Ward but now it's getting a little bit better.
P/S 3: I only play COD 2 (Demo), BO (Pirated), MW3 (Pirated), so not much known about the multiplayer part.
P/S 4:Consider it my personal comparation.

whoever buy from Impulse, they use Skynet....yesterday got public holiday. Tomorrow also.

The game might arrive on Friday or Saturday
dafuq man.

How do I know I'm in a double exp lobby? Seems like no difference

It only appear on console.