Just for reference here is the average PC setup based on Steam's hardware Survey.
Intel CPU Speeds
2.3 Ghz to 2.69 Ghz
Video Card Description Intel HD Graphics 3000
Primary Display Resolution
1920 x 1080
Total Hard Drive Space
250 GB to 499 GB
These specs wouldn't be so bad was it not for Intel's integrated graphics which are pure shit for gaming.
I hope Valve's "SteamBox" and AMD's APU line will eventually surpass Intel's graphics crap.