Heavy Rain Is A System-Seller According To David Cage.

Aptly, that term is "system seller", and Quantic Dream's David Cage thinks Heavy Rain is just that.
“This experience should be available exclusively on PlayStation 3, and we want people to buy a PlayStation 3 because of Heavy Rain. We’re really happy at the moment – and I hope it’s going to last – that when we go onto forums we find people watching the trailers and stuff and saying ‘this is the game that’s going to make me buy a PlayStation 3?,” said the Quantic Dream boss.</blockquote>

With Heavy Rain being such a unique experience, we wouldn't put it past people picking up a Playstation 3 to try the game. Either that or they'll just proclaim, "Do not want QTE only game," on GameTrailers' forums.