I think Nintendo really needs to rethink its marketing strategy, big time! The fact last year they caused the same high demand - low supply brouhaha by introducing something many people wanted badly but not manufacturing enough units was a big mistake, and as Leighdu points out, you'd think that a company like that would want to make its customers happy by making more units.
Whether this is a corporate decision to drive up demand or if Nintendo is having problems with its parts supplier chain, I don't know. I am not a gamer, mind you, but I have friends whose kids want a Wii and have had to wait another Christmas without one.