Here is a more interesting look at the data for you.
http://vgchartz.com/hwlaunch.php?cons1=Wii®1=America&cons2=PS2®2=America&cons3=DS®3=America&weeks=175&weekly=1
The DS is selling at a higher rate then the PS2 in the same time frame. The PS2 just happened to have a larger bump in it's second year.
Care to retract your statement?