-Four-player co-op is confirmed.
-You'll play at least two characters in multiple international conflicts.
-American and Russian black operatives have been consulted. Given the above points, we reckon that means you might play on both sides of the conflict
-As black ops teams were privy to superior intelligence and had free access to any equipmenent they wanted, weapons and ammo will be more varied this time around. A military crossbow has been confirmed so far, but it's not just for sniping. CoD:BO (unfortunately aromatic acronym) allows on-the-fly ammo changes for some of its weapons, so the bow can also be fitted out with exploding arrows.
-There's also an AUG assault rifle that will take multiple attachments.
-The SR-71 Blackbird is the new AC-130. During one level, the recon plane is used to observe terrain from above, with the player directing the squad below with a pointer in order to help them avoid enemy Russian convoys. Immediately after this, you'll take control of the squad on the ground.
-Treyarch head Mark Lamia has said that the game is 'epic in scope', being focused around a story that 'has meaning and character and will be multi-threaded'. Perhaps more of an indication that Treyarch will be giving the Cold War an ambiguous, mutli-sided treatment?
-CoD: BO is using the same full-actor motion-capture technology as Avatar. That means that not just gestures, but whole performances are captured, right down to facial expressions and line delivery. Expect some serious emoting this time around.
-It looks like Treyarch is following Modern Warfare's lead in terms of big action movie set-pieces. Cliff-diving and rappelling through windows are already in.

Reference:http://www.gamesradar.com