According to Steam, this year should be their largest yet in their six year run. Impressive numbers considering WoW just updated their stats to the
12 Million mark on Oct 7 2010. These are active users as well, not just accounts and peak simultaneous players has reached 3 million. To offload some of that strain, Valve has increased it's infrastructure to a whopping 400Gps. Steamworks can also claim integration in over 200 titles and many of this years biggest hits.
PC Gaming in jeopardy indeed!