So what exactly is Heavy Rain about?

Its about A LOT of rain,

No serious i have no idea

LOL, not quite what I had in mind... Well, if that trailer had nothing to do with the story, just a tech demo, then err... well it looks great first of all, and I'm kind of thinking it will be either a third person shooter or an rpg (kind of obvious but hard to take a shot in the dark ). Hoping that it's not like, adventure/puzzles.

Also hope the main character really is female. We need more of those.

I'm guessing is something like Indigo Prophecy. A game where you're put in the shows of a character in an extreme position.

Like the poor nameless bastard in the trailer who comes home to his wife.:) ... :(

It's supposed to be a murder mystery game.

It recieved a subtitle called "The Origami Killer"

Unfortunately, that's all we know