Here's the VGC chart:
http://vgchartz.com/hwlaunch.php?cons1=Wii®1=America&cons2=PS2®2=America&cons3=X360®3=America&weeks=156
It for the whole Americas, not just US, so it doesn't correspond perfectly, but we can see that the Wii is at least 3 million units ahead of the PS2, and the current slope of the Wii line is a little steeper than the PS2's was at this point in its life.

"The worst part about these reviews is they are [subjective]--and their scores often depend on how drunk you got the media at a Street Fighter event." — Mona Hamilton, Capcom Senior VP of Marketing
*Image indefinitely borrowed from BrainBoxLtd without his consent.







