Most sports have yearly world championships and they get only a smidgeon of the attentions given to the Olympics. The Olympics take sports like swimming, rowing, track and field, and gymnastics (my personal favorite) and turn them into a Super Bowl.
Maybe it's because all the different sports are at the same place and time and because the athletes are representing their countries. Maybe the media creates enough of a circus to draw most eyes to the spectacle. Whatever it is I am hooked and will watch the 2012 Olympics closely, rooting for my favorites, because the Olympics are AWESOME!