Yeah, because Blizzard makes great games that were PC only, and Valve did too until recently. Diablo III and Starcraft 2 will sell like gangbusters, because people understand how much time and effort Blizzard spends on their products. Valve also spends a LOT of time on their games. Neither company values technology over substance and quality. I only wish more companies are like this. Set the system requirements to current day realistic values, and make it very fast on those systems. Forget about the top-end, it's worthless to try since the amount of people with systems that powerful isn't nearly as valuable as getting it to run on the low end in two years time.
For every Half-Life 2 or World of Warcraft there is a terrible Far Cry 2, which hardly runs on any system and isn't a very interesting game, or an Age of Conan, all style over substance.