Call of Duty: Black Ops 2 guns

We have had many looks at the Black Ops 2 guns just through the trailer. But one I really like, one is a very customizable gun in real life. In real life it can be customize to be a SMG, 2 types of Ausult Rifles, or an LMG. many of the guns may be like this. Also they had x-ray vision so this makes me think that if you get a big enough kill streak then you may be able to put an attachment on your gun the allows you to see through walls and kill the enemy.