I think the PCGA gave the total PC gaming market at around $13 billion for 2008- I haven't seen a figure for last year, but with the massive growth in Steam, some big releases (Dragon Age, Borderlands, L4D2, COD 6 etc etc) and the continuing success of WoW, other MMOs and various Facebook games, I'd be surprised if it didn't grow nicely. Also, about 80 million graphics cards were sold last year- they won't be being bought by businesses.