I supposed I should've said, sales trends don't suddenly reverse themselves *within a generation*.
PS1 started off slowly everywhere but was never behind since it had nearly a 2-year headstart on the N64 and the Saturn just sucked.
PS2 took off like a rocket everywhere, caught DC easily and had a 15 million lead by the time XB and GC even launched.
Wii is following the PS2 curve very closely, but didn't have a headstart.
PS3 is tracking somewhat above GC/XB numbers but nowhere near PS2, though it's been doing a bit better since Xmas with the agressive pricing/bundling/advertising.