The PC Gaming Alliance has released its annual Horizons report to its members, and a press release to the rest of us. Said release indicates that PC gaming hardware sales were pretty healthy in 2009, totaling "over two times larger than the combined Wii, PlayStation 2, PlayStation 3 and Xbox 360 console units shipped in the same period." They also make some predictions about the future, saying that "the worldwide number of consumers gaming with discrete graphics solutions on their PCs (Desktop and Notebooks) to be 212.6 million for 2009 and expects this to grow to about 322 million by 2014."
I suppose we can draw some conclusions from that, eh? (And, as for software, which folks have been talking about in the comments, this NPD report is all we have at the moment.)