The new Medal of Honor has already sold 1.5 million copies, despite terrible reviews.
A wise man told me that video games are like fruit at the moment - people just buy whatever is in season.
At the risk of sounding like an elitist gamer, there are so many better games. I'd rather stick to games I enjoy (Skate 3, Brutal Legend, Red Dead Redemption, Final Fantasy, Kingdom Hearts) no matter how old they are (Grim Fandango anyone?) than just go out and buy something because its new.
Although, pictured below is a game I will probably buy on impulse - it looks that good.