The actual trailer has been released for CoMW2 by Infinity Ward. It shows ingame rendered scenes and some of the weapons and vehicles that could be in the game. It now has a confirmed release date of 10th Novemember 2009.

http://www.youtube.com/watch?v=CN6517n1xDw

From GameReplays.org:

From the video we are able to establish some of the possible weapons that will be in the game (unconfirmed):

Amsel Striker 12
Mk .46 LMG
SR-25
W1200
KRISS Super-V
Desert Eagle
AK-47
AK-101
Glock-22
M4 Carbine
Suppressed M14
F2000
MD-3
Steyr AUG
UMP
M16
SAW
M203

From the trailer we are also able to get an insight into a few of the locations and scenes Modern Warfare 2 may take us to (unconfirmed):

Suburban setting, most likely Rio de Janeiro
Snow setting, possibly Siberia.
Underwater location
Multiple hostage situations
Abandoned airfield
Airport setting