Just wait until they enable the inter-compressioon on these new drives. It works like this... See, all that's recorded are 1's and 0's. Well as you can see, the 0's are right fat little bastards. So some sneaky scientist type has figured out how to stick the ones right through the middle of the zeros. This ends up taking less space. In fact they're already working out how to double-stuff those 0's - soon we may see two or three ones in each.
And before you get all up in my face saying this is old news, you were probably thinking of the older technology that didn't pan out which was to put the zero above the one to look like those cute "i's" that some girls write. At today's high platter rotation speeds however, they found that some of the 0's would fly loose and gum up the spindle motors.
Bruno