The Wii has the curve of the winners, just between the PS2 and the DS :
http://vgchartz.com/hwlaunch.php?cons1=Wii®1=Japan&cons2=PS2®2=Japan&cons3=DS®3=Japan&weeks=55
Though it will unlikely have the same christmas as the DS, which sold 300k, 400k, 600k and 400k on the four weeks of it's second christmas.