Kinda what yoshi said. Sales in the first half of 09 were down rather significantly from 08, so production was reduced. However, December came along and blew away sales records, forcing Nintendo to airship some of 2010 Q1's Wii's to retail for the holidays. However, this means that Nintendo doesn't have the reserves to replenish retailers now, and as such, are shipping them out as they make them. I don't know if Nintendo's trying to ramp up supply again for a few months to have another safety cushion or not (though I think it'd be good if they did), but it's forecast to go through at least the end of March...
-dunno001
-On a quest for the truly perfect game; I don't think it exists...