Of course they stockpiled. They didn't come to december with only 1.8M Wiis to sell worldwide, that would be totally stupid.
Actually I think there's a mistake in your numbers, Nintendo was producing 1.2M Wiis a month til August. That would make 1.6M more consoles produced.
Actually we don't know precisely how many Wiis have been produced every month, we don't know either when exactly the production rose, and we don't know exactly when all those consoles produced were shipped.
All we know is that when making a quick calculation with the few data we have, the numbers are quite well coinciding. And we also know that Nintendo doesn't have much Wiis left in stock and will probably be almost soldout after christmas.







