With hardware penetration at the level it is at already no and I mean no software title left will produce signifigant change to consoles sales. Sure a mild bump may happen because of a title, but nothing major enough to change the hardware sales patterns. Quality software for each console (besides the Wii) keeps the consoles fresh and keeps hardware selling, just doesnt change the pattern. If quality software stopped coming at a regular basis you would see hardware sales drop.
Its libraries that sell systems not a single game.