Multi-core in the Source Engine

"We have been continually surprised by the rate of adoption of new hardware," says Gabe, referring specifically to the Hardware Survey that Steam extends to its users. Valve is clearly expecting a fairly rapid uptake of quad-core as Intel and AMD push it out next year. "We also have the massive advantage of Steam. It gives us the ability to sell to people - we know how many cores your system have, we know what kind of content is right for the hardware configuration that you have. If you try to sell quad-core content to people in retail, you'll fail utterly, because the density of people walking in with those kinds of systems will be low. But with Steam, we can reach out to those people directly."

Check it out at Bit Tech.