IDG has released their predicted hardware and software sales through 2010 with Next-Gen summarizing key points from the console guestimates. The market research firm believes that by the end of the decade the Xbox 360 will have sold 23.9 million units, the PS3 23.5 million units, and Wii 13.6 million units. So in four years, North America and Western Europe will have sold about the same number of 360s as the Xbox's 24 million worldwide, PS3 significantly lower than 106 million worldwide PS2 sales, and Wii selling fewer than the GameCube's current 21 million worldwide.
Good thing the firm used decimal points to suggest accurate predictions. So how do they make said forecasts? Darts on a graph, of course!
[Whoops! My "dumbness" forgot to mention the report is for North America and Western Europe only]