and you consider that a commercial success?

^^
http://en.wikipedia.org/wiki/Fahrenheit_(video_game)
Fahrenheit (Indigo Prophecy) sold 800k across several platforms, but I don't know how much the best selling version sold, VGC http://www.vgchartz.com/games/index.php?name=indigo+prophecy reports only 100k for the XB version, so the best selling of the other 3 must have sold at least 230k.

yes french and dutch (the fucked up language :) ) I did my work and preordered it.

Whether this game sells or not will depend a lot on review scores (hardcore crowd kind of game) and advertising (which Sony likely won't do for a game like this). We'll know soon enough. Also, thank you Sony for investing in something different.

That said, I have two concerns for this game.

First, being a story based game means the story better be very well told. To be good means the pacing, script, and voice acting will have to be spot on. If any of these are even a little bit off the whole thing might suck. Specifically, I'm worried about the dialog being translated over from French to English (can you say lost in translation), the lack of high profile voice actors (try adding a few stars names to the cast, and on the box, if you want quality and sales), and pacing a movie style experience across 10 hours.

Second, I hope the choice for interacting with the environments/characters is logical. In traditional games the jump button always jumps, the shoot button always shoots, etc. The controls in this game should be logical and stay consistent in the same way. for example, in combat situations, defending or escaping should always be the same buttons, counter attacking should always be the same button, and in exploration mode, examine should always examine, pick up should always pick up, open a door should always open door, etc.. Otherwise the whole game will be spent staring at the controller instead of the screen and the player will feel very disconnected from the action.

Fingers crossed on this one. If it works, and sells, an entire genre may be re-born.

I don't think high profile actors are automatically a good thing.  Jennifer Lopez and Ben Affleck starred in Giglo, one of the biggest critical and commercial flops ever in the movie industry.  Also, I doubt Jack Black can pull off that high quality VA that he did in Brutal Legend in every movie he is in.  The VA for Heavy Rain sounds good to me so far.  I don't get the "lackluster voices" comments.  I even heard from one site that the characters sounded like French actors trying to sound English by they sound American to me.

^^
Ben Assfleck is largely overrated!!!

For the kind of game it is yes. BTW I'm also being kinda conservative on my numbers.

your definition of commercial success is flawed, if that is considered succesfull for the series, nobody will produce  such games. 

500k may be a flop, but with 700k I'm sure the game will turn a small profit.

Considering how much was invested in Heavy Rain at least 2 million should be considered a slight success.