It isn't a chicken and egg question. It has always been a case of both. Software people ask the hardware people for more power so their applications can do new, more, faster things. Hardware people always improve their designs for efficiency, speed, capacity. Both camps interlock and have visions of what could be.

Computers didn't improve because some guy said "I have this idea for a game with complex graphics". It improved because a scientist said "I think we can visualize this huge data set", and that filtered down into consumer systems. SGI was doing high end graphics a long time before anybody made a 3D gaming card.

Of course you don't really have to be a visionary to think entertainment will sell.

The reason this question has been removed is not because it isn't a cool question, but because it is almost certain to break our 20 year rule on the sub. =/ I am truly very sorry.