That event where they "proved" it could run on a machine that only cost $900 was more like 3 months after release. 3 months in computer hardware may as well be a lifetime. But fact is, people shouldn't have to buy a whole new computer just to play a single game. PC Games need to be minimum 2 years (if not more) backwards compatible with hardware. Crysis ran like shit on some PC's that were bought less than a year prior to the release.

I'm not talking about an "event" they held, I'm talking about my own fricken build I put together:

$105 - Windows Vista Home Premium
$55 - Highly-rated 550W Power Supply
$30 - Highly-rated case
$190 - 2.66GHz Core 2 Duo E6750
$95 - Fantastic Gigabyte P35 motherboard
$50 - 2GB Ram (only 800MHz, but highly-rated)
$270 - 8800GT (in and out of stock so often, you'll eventually find one)
$50 - 160GB SATA hard drive
$32 - DVD-RW drive

Total - $877

I created that build on December 4th, merely two weeks after Crysis came out. It's more than capable of running Crysis on High detail and 1680x1050, considering that my much slower computer - an opteron 165 with 2GB of PC2700 ram - could do so throughout the majority of the game.

Crytek themselves did it a month later:
http://www.neogaf.com/forum/showthread.php?t=228249