Infinity Ward’s Vince Zampella has said that Modern Warfare 2 will focus more on entertainment that realism.
“We go for authenticity not realism,” Zampella told Official PlayStation Magazine. “We’re not making a sim, we’re making entertainment. We want it to look real like an action movie.
“You see a guy in an action movie, what he does is a little over the top. It makes for a great movie.”
That should explain why you will be using a futuristic gun with lasers on a tripod that detects and shoot enemies.