Infinity Ward has confirmed that there will be no demo released for Modern Warfare 2 before the game's November 10th launch date.
Making the announcement on "No plan for a Demo before launch. The entire team is focused on polish all the way up to ship of the full game.", a spokersperson said:
It looks like we'll have to wait until the said launch date until we can get our hands on the latest Call of Duty game. Can you wait that long gamer?