One of the few objections gamers are already making about Gears of War is that there is no jumping. Every time a developer decides to disregard a jumping option, gamers cry a river. Sometimes, gamers are right, such as with Perfect Dark Zero. In other cases, the way the game has been designed requires that there is no option for jumping at all. That's the case of Gears of War.
According to Cliff Bleszinski, Gears of War's lead designer, jumping in shooters is reminiscent of the Mario and Sonic era. CliffyB says people jump because it is the fastest way to move throughout a level, but in a game like Gears of War, where you move from cover to cover, you're already jumping-just in the X and Y axes.
In the following movie, CliffyB fully explains his reasons for the lack of a jump button in GoW: