http://www.reghardware.co.uk/2007/07/09/ps3_sixaxis_rumble/
"The rumours stem from a picture of the design of the 80GB PS3's box, which was released alongside Sony's announcement, and which shows the controller with an illuminated red button in the centre.
On Sony's PS2 controller the equivalent of the red button, a square LED, was used to indicate the operation of its rumble capability, which makes the controller... well... rumble in time with gun shots, car crashes, etc while playing a game.
Sony has yet to comment on the presence of a rumble feature on the 80GB PS3 controller, but some gamers are speculating the feature, also referred to as Touch Sense, will be an improvement on the PS2's rumble capabilities by making its vibrations more akin to what's taking place on screen."
I think if the 80 Gig model really does have rumble it would have greater positive effect on sales as it's a clearer and more immediate hardware benefit then just 20gigs of extra space.
"..just keep on trying 'till you run out of cake"
