At the end of the Call of Duty Black Ops trailer, Woods can be seen holding a Colt M1911 handgun with the name 'Sally' scratched into the side.
The 'Sally' M1911 can be seen on the game's box if the player looks closely at the handgun on the left side of the box. This implies that Woods is the mysterious person on the front cover.
It is also possible that the mysterious man is Mason, holding Woods' M1911 that he used after Woods died.