I caved. I had to give this one a try since I'd heard so much about it. I've only played about an hour into it so far and yeah, I'm completely blown away by the graphics.
I'm running it in 1680x1050, all graphics options on High, with textures on Very High, and I'm using 8x anti-aliasing. The game looks and runs unbelieveably well. Seems to be a lot of fun so far too. The foliage in the jungle is just amazing from a detail perspective.
Pretty game, but kind of meh gameplay-wise. As far as I can tell, it basically exists as a hardware-straining/upgrade-selling solution with a game attached