Just a theory on the Wii, but maybe Nintendo diverted a bunch from the US to Japan to coincide with the Wii Fit launch. They have to shuffle around a fixed amount of consoles, so they're juggling the holidays here and in the rest of the world and a major launch in title in Japan. They put a lot of advertising and effort into Wii Fit in Japan.
Just my thoughts, because the WW sales from last week and this week look pretty even.
3rd Party Wall of Shame
http://www.nintendoworldreport.com/forums/index.php?topic=30478.msg581036#msg581036