In an exclusive preview (for USATODAY) of one level, game developer Treyarch wanted to demonstrate "the game is epic in scope," says studio head Mark Lamia.
Here some snippets:
"Beyond the single-player story, the game will have a cooperative mode for two to four players and an online multiplayer mode."
"The modified military crossbow seen in the preview level, Lamia says, "is a great example of how elite black ops teams were permitted to equip themselves for whatever job they had at hand, which means that they could get a hold of anything and modify it any way they wanted to accomplish their missions objectives. The specific crossbow in the game is based off the design of a military grade crossbow."
USATODAY INTERVIEW: Treyarch studio head Mark Lamia
ALSO: More on the preview level of 'Black Ops'

Another Trailer Breakdown can be found
HERE