I honestly think that there are two forces at play here, Nintendo being overly carful and the Wii feedback loop.
I could be wrong but I suspect Nintendo's approach to manufacturing is to
- Introduce new production
- Observe reaction to new production (2 months)
- If production levels are not adequate work towards increasing production (2 months) and goto 1
This cautious approach means that they're unlikely to overshoot demand by much but also means that production increases take time.
At the same time everyone who buys a Wii ends up showing it off to all of their gamer and non-gamer friends which causes a large portion of them to want one of their own. This feedback loop means that as production increases to meet demand, demand increases beyond what can be supplied. This loop is probably not going to be active forever but is probably causing endless problems for Nintendo as they try to figure out how many systems to produce.
