TheCheese33: This is one game (like Uncharted) that used the controller so well that I doubt it would benefit from a PC release. Also, getting it to support low-spec computers could be a logistical nightmare, and the game used SIXAXIS support in specific spots (and used it well).
I don't know about uncharted but there is nothing in Heavy Rain that really "require" a Sixaxis, most of it's use is gimmicky, in the end a QTE is a QTE, shake the controller to bash through a door or press space to bash through the same door achieve the same result.
For the rest; the quarter circle with the stick to open a door can easily be done with a mouse and the "tilt the controller to keep balance" parts can be done with left and right keys.
The only parts that would actually be difficult on PC, without a controller at least, is the parts where you have to press 5-6 buttons together as some keyboard configuration tend to not like having that much keys pressed at once.
