I bought the game from Steam a few hours ago, and I noticed that the game requires 4 GB of RAM and a Gtx 460 to run. I already ordered the game before I read them so I couldn't do anything but wait and see if it will run after it finishes downloading.
And lo and behold, the game runs with no problems. Not only that, but I can run it at 1680 by 1050 with everything maxed out including FXAA antialiasing selected (it doesn't say a number). And for the most part it runs at 60 fps. Im on the second mission and the lowest I've seen it drop is 41 fps (and that happened during those interactive cutscenes where I can move the camera around a bit).
During gameplay its usually 60, even when there is a lot of stuff on screen (enemies and large background vistas). It sometimes drops at like 52, but rarely (as I said, only during those cutscenes actually dropped in the forties).
So my question is, why are the minimum requirements so high? If my GTX 285 can run it at these details and framerate, I imagine there are even slower cards that can run it well at lower resolutions and 30 fps. Also, I have 2 GB of RAM (which is below the minimum of 4 GB) and I only experienced a bit of stuttering ocasionally. And I read on the internet that it runs on XP with SP3 right out the box, even tho it doesn't support it. (I'm running 7).