To further back up my point, this is 2 years of PS2 sales from launch in Japan. This is 2 years of the 360 and PS3 from launch of the 360. This does not align launches, since in this case, total usebase after a given time is more important than saying how many it sold each year.
PS2 after two years (with only about 1.5 for NA and Others): 24.5 million
PS3+360 after two years (with only 1 year for PS3, and only 8 months for PS3 other): 20.5 million. It is only a 4 million difference, but since we're combining two systems, I think 4 million is quite a lot. Especially when you consider that the Wii has 20 million after only 14 months, though it had very close WW launches.
Edit: Forgot to add the links.







