Originally posted by another user
1. SINGLEPLAY
1. - The physics on bullets and grenades have become more realistic. Bullets will now ricochet, and grenades will bounce down stairs, or roll down inclines, like they would in real life.
2. - You can now hold a pistol in one hand, and a knife in the other. In doing so the knife hand supports the gun hand. Knifing will now become even more popular.
3. - We’re going under water. Why else would they show us a extremely cool, heavily armed SEAL diver?
4. - We glimpsed a level with the name ‘International Cyber Space Lab’ We aren’t going into space are we? Or was this a abandoned Russian missile base.
5. - Bullet time will make it’s debut in CodMW2. Hold your horses!, it won’t be FEAR, ramming on yellow if you get into trouble. Bullet time will only occur when the developer wants it to, and will be used more like a dramatic effect during an explosion, allowing you to take out those few extra enemies.
6. This time around, there will be more innocent bystanders.
2. MULTIPLAY
1. - There will be a number of new modes in multiplayer. More about this will be only made public after E3, but they are modes we aren’t seeing in other games yet. The menu structure from which you start multiplayer sessions, will be changed as well because, and we cite Bowling, “there will be too many extra things, that we want to present in a decent manner”. And oh yes, the music will change too. We know it all to well by now.
2. - Perks like Martyrdom changed the shooter genre in a pleasant way. Other shooters happily steal the perk system from Infinity Ward, but they don’t care one bit, because in CoDMW2, they will have a number of new perks that will undoubtedly be a pleasant surprise for the community.
3. - The riot shield will be, for a 100% sure, a perk. Bowling let it slip, that you’ll be able to carry two shields with two guys, and that a third player could, while taking cover behind the two gents, open fire on the enemy. How sick is that?
4. - Good news for everyone hating on dudes that decide to walk out in the middle of a game. Bowling wouldn’t say how, but he indicated that there would be “options to act on that”. We’ll be keeping him to his word, because if there’s something we hate.